Force clear all timeouts when pausing test execution

[nevadascout]

In rare cases the "test run in progress" indicator can continue running after a test run is finished. The only way to reset the UI is to restart VS Code.

Instead, we should force clear all timeouts when pausing test execution.

http://stackoverflow.com/questions/8860188/is-there-a-way-to-clear-all-time-outs#8860203