Separate unit and functional test execution

[arthuraraujo-msft]

Request made by @JeffMill

cd build/client
ctest --verbose --progress

several tests take a while (relatively speaking) to run. UTs should be instantaneous. Should split out FTs to seperate test.

[arthuraraujo-msft]

We can probably move enable_testing to the test/unit and tests/functional, which will make ctest have to be run like ctest --test-dir builc/client/tests/unit

The test script can have switches to choose either or both