Infer test group name directly from test file path

[yiyun-sj]

Test Group Name Generation

• uses the relative file path as test group name
• delimiter choice is '~' ('.' is reserved by gtest, '/' is reserved by file path)
• current -GROUP property is not removed for backward compatibility (is this necessary?)

Note: some characters such as : and - result in tests not being actually run (some current test cases are like this)

Example the file test/test_files/tck/match/match8 now has test group name tck~match~match8

Todo delete -GROUP from all existing test files (do we want to do this?)

[ray6080]

Also, can u revisit the false positive issue? We'd better understand what's acceptable directory and file naming conventions under test_files.