Enable verbose mode on c++ unit tests

## Feature Request

This a proposed change to an existing feature on the C++ unit tests. It would be nice to run the tests in verbose mode.

## Description

If we add the verbose mode switch to ctest we can know which subtest within the test caused the failure. Currently the output looks like this:
```
Test project /Users/nelsonr/git/public/OpenTimelineIO/_build
Start 1: test_opentime
1/2 Test #1: test_opentime .................... Passed 0.01 sec
Start 2: test_clip
2/2 Test #2: test_clip ........................ Passed 0.01 sec

100% tests passed, 0 tests failed out of 2
```
By adding the -V switch we will have this:
```
test 1
Start 1: test_opentime

1: Test command: /Users/nelsonr/git/public/OpenTimelineIO/_build/tests/test_opentime
1: Test timeout computed to be: 1500
1: Running test test_create
1: Running test test_equality
1: Running test test_inequality
1/2 Test #1: test_opentime .................... Passed 0.56 sec
test 2
Start 2: test_clip

2: Test command: /Users/nelsonr/git/public/OpenTimelineIO/_build/tests/test_clip
2: Test timeout computed to be: 1500
2: Running test test_cons
2: Running test test_ranges
2: Running test test_clip_v1_to_v2_null
2: Running test test_clip_v1_to_v2
2: Running test test_clip_media_representation
2/2 Test #2: test_clip ........................ Passed 0.02 sec
```
If we get a failure, this will allow us to know which subtest caused the failure.

Start by locating the CTest configuration and the command that runs the C++ unit tests. Enable CTest verbose output with the requested -V switch, then run the test suite and confirm that individual subtests are shown so failures identify the failing subtest.

Written by the indexing model from the issue text.