Repeated version

[mfateev]

What was changed

The new Workflow.getVersion overload to support versioning signal and other handlers as well as loop bodies.

Why?

Consider the following example:

for (int i=0; i<100; i++) {
     if (getVersion("fix1", DEFAULT_VERSION, 1) == DEFAULT_VERSION) {
         // OLD CODE
     } else {
         // NEW CODE
     }
}

If the change is introduced after the loop starts executing, all iterations are going to use
the default version, even if most of them happen after the change. This happens because the *
getVersion call returns the same version for all calls that share a changeId. The same issue *
arises when changing code in callbacks like signal or update handlers. Frequently, there is a
need for a new version used for newer iterations (or signal handler invocations).

The following solution supports updating the version of each iteration separately, as it
uses a different changeId for each iteration:

    for (int i=0; i<100; i++) {
        if (getVersion("fix1-" + i, DEFAULT_VERSION, 1) == DEFAULT_VERSION) {
            // OLD CODE
        } else {
            // NEW CODE
        }
    }

The drawback is a marker event as well as a search attribute update for each iteration. So, it
is not practical for the large number of iterations.

The newly added method provides an efficient alternative to the solution that uses a different changeId
for each iteration. It only inserts a marker when a version changes.

Here is how it could be used:

    for (int i=0; i<100; i++) {
        if (getVersion("fix1", String.valueOf(i), DEFAULT_VERSION, 1) == DEFAULT_VERSION) {
            // OLD CODE
        } else {
            // NEW CODE
        }
    }

2. How was this tested:
   A unit test was added.

3. Any docs updates needed?

Patching documentation for Java SDK should be updated.