I have a few changes here. Some of them might not make it depending on how others feel.

- Move test utilities in to a library to share across tests.
- Move tests in to individual executable to enforce individual tests to not sharing code.
- Use `gtest_discover_tests` to let `ctest` run and show all tests individually.
- Use `gtest::gtest_main` and remove explicit main entry file.
- ~Build and run tests by default.~
- Ability to filter tests by `ctest --test-dir build -R "TestCuda.*"`

```
+ echo 'Running CTest...'
Running CTest...
+ ctest --test-dir build
Internal ctest changing into directory: /workspaces/morpheus/build
Test project /workspaces/morpheus/build
      Start  1: TestCuda.LargeShape
 1/35 Test  #1: TestCuda.LargeShape .......................................   Passed    0.17 sec
      Start  2: TestDataLoader.DataLoaderInitializationTest
 2/35 Test  #2: TestDataLoader.DataLoaderInitializationTest ...............   Passed    0.07 sec
      Start  3: TestDataLoader.DataLoaderRegisterLoaderTest
 3/35 Test  #3: TestDataLoader.DataLoaderRegisterLoaderTest ...............   Passed    0.07 sec
      Start  4: TestDataLoader.DataLoaderRemoveLoaderTest
 4/35 Test  #4: TestDataLoader.DataLoaderRemoveLoaderTest .................   Passed    0.07 sec
      Start  5: TestDataLoader.PayloadLoaderTest
 5/35 Test  #5: TestDataLoader.PayloadLoaderTest ..........................   Passed    1.42 sec
      Start  6: TestDataLoader.FileLoaderTest
 6/35 Test  #6: TestDataLoader.FileLoaderTest .............................   Passed    2.65 sec
      Start  7: TestControlMessage.InitializationTest
 7/35 Test  #7: TestControlMessage.InitializationTest .....................   Passed    0.07 sec
      Start  8: TestControlMessage.SetMessageTest
 8/35 Test  #8: TestControlMessage.SetMessageTest .........................   Passed    0.07 sec
      Start  9: TestControlMessage.TaskTest
 9/35 Test  #9: TestControlMessage.TaskTest ...............................   Passed    0.07 sec
      Start 10: TestControlMessage.PayloadTest
10/35 Test #10: TestControlMessage.PayloadTest ............................   Passed    1.45 sec
      Start 11: TestDataLoaderModule.DataLoaderModuleInitializationTest
11/35 Test #11: TestDataLoaderModule.DataLoaderModuleInitializationTest ...   Passed    0.07 sec
      Start 12: TestDataLoaderModule.EndToEndPayloadDataLoaderTest
12/35 Test #12: TestDataLoaderModule.EndToEndPayloadDataLoaderTest ........   Passed    0.12 sec
      Start 13: TestDeserializers.GetIndexColCountNoIdxFromFile
13/35 Test #13: TestDeserializers.GetIndexColCountNoIdxFromFile ...........   Passed    1.39 sec
      Start 14: TestDeserializers.GetIndexColCountWithIdxFromFile
14/35 Test #14: TestDeserializers.GetIndexColCountWithIdxFromFile .........   Passed    1.37 sec
      Start 15: TestDeserializers.GetIndexColCountNoIdxSimilarName
15/35 Test #15: TestDeserializers.GetIndexColCountNoIdxSimilarName ........   Passed    0.19 sec
      Start 16: TestDeserializers.GetIndexColCountIdx
16/35 Test #16: TestDeserializers.GetIndexColCountIdx .....................   Passed    0.18 sec
      Start 17: TestDeserializers.GetIndexColCountValidNameInvalidType
17/35 Test #17: TestDeserializers.GetIndexColCountValidNameInvalidType ....   Passed    0.16 sec
      Start 18: TestDevMemInfo.RmmBufferConstructor
18/35 Test #18: TestDevMemInfo.RmmBufferConstructor .......................   Passed    0.16 sec
      Start 19: TestDevMemInfo.VoidPtrConstructor
19/35 Test #19: TestDevMemInfo.VoidPtrConstructor .........................   Passed    0.25 sec
      Start 20: TestDevMemInfo.MakeNewBuffer
20/35 Test #20: TestDevMemInfo.MakeNewBuffer ..............................   Passed    0.25 sec
      Start 21: TestFileInOut.RoundTripCSV
21/35 Test #21: TestFileInOut.RoundTripCSV ................................   Passed    2.67 sec
      Start 22: TestFileInOut.RoundTripJSON
22/35 Test #22: TestFileInOut.RoundTripJSON ...............................   Passed    2.69 sec
      Start 23: TestMatxUtil.ReduceMax1d
23/35 Test #23: TestMatxUtil.ReduceMax1d ..................................   Passed    0.17 sec
      Start 24: TestMatxUtil.ReduceMax2dRowMajor
24/35 Test #24: TestMatxUtil.ReduceMax2dRowMajor ..........................   Passed    0.17 sec
      Start 25: TestMatxUtil.ReduceMax2dColMajor
25/35 Test #25: TestMatxUtil.ReduceMax2dColMajor ..........................   Passed    1.40 sec
      Start 26: TestMatxUtil.Cast
26/35 Test #26: TestMatxUtil.Cast .........................................   Passed    0.16 sec
      Start 27: TestMatxUtil.Threshold
27/35 Test #27: TestMatxUtil.Threshold ....................................   Passed    0.16 sec
      Start 28: TestMatxUtil.ThresholdByRow
28/35 Test #28: TestMatxUtil.ThresholdByRow ...............................   Passed    0.19 sec
      Start 29: TestMultiSlices.Ranges
29/35 Test #29: TestMultiSlices.Ranges ....................................   Passed    1.37 sec
      Start 30: TestTensor.UtilsShapeString
30/35 Test #30: TestTensor.UtilsShapeString ...............................   Passed    0.06 sec
      Start 31: TestTensor.GetElementStride
31/35 Test #31: TestTensor.GetElementStride ...............................   Passed    0.06 sec
      Start 32: TestTensor.AsType
32/35 Test #32: TestTensor.AsType .........................................   Passed    0.16 sec
      Start 33: TestTensor.Create
33/35 Test #33: TestTensor.Create .........................................   Passed    0.16 sec
      Start 34: TestTensor.UtilsValidateShapeAndStride
34/35 Test #34: TestTensor.UtilsValidateShapeAndStride ....................   Passed    0.16 sec
      Start 35: TestTypeUtils.DTypeCopy
35/35 Test #35: TestTypeUtils.DTypeCopy ...................................   Passed    0.06 sec

100% tests passed, 0 tests failed out of 35

Total Test time (real) =  19.91 sec
```

Authors:
  - Christopher Harris (https://github.com/cwharris)

Approvers:
  - David Gardner (https://github.com/dagardner-nv)

URL: #1095