Implement the extended scope and further improvements for ktxtools

[VaderDev]

This PR completes the original and the extended scope of ktxtools. Some of the scope was already part of the previous PRs.

Briefs:

• tools: Implement stdout support
• tools: Implement stdin support
• tools: Implement 4:2:2 support
• tools: Implement support for 10X6 and 10X4 formats
• tools: Implement support for B10G11R11_UFLOAT and E5B9G9R9_UFLOAT formats
• tools: Complete support for Depth-Stencil formats
• tools: Improvements, cleanup and bug fixes
• extract: Implement fragment URI support
• extract: Implement 4:2:2 sub-sampling
• validate: Fix and extend padding byte validation checks
• cts: Add support for stdin/stdout test cases (including binary IO)
• cts: Add tests to cover new features and capabilities
• cts: Extend existing tests to improve coverage
• cts: Test runner now deletes matching output files (this enables easy packaging of mismatching files)
• cts: Added a new cli arg to the runner script: --keep-matching-outputs to prevent the deletion of matching output files
• dfdUtils: Implement 4:2:2 support
• dfdUtils: Implement support for 10X6 and 10X4 formats
• imageio: Fix stdin support
• ktx: Add stringToVkFormat to mkvkformatfiles
• ktx: Implement 3D BC support (ASTC 3D Blocks)
• ktx: Implement 4:2:2 support
• ktx: Complete support for Depth-Stencil formats
• ktx: Improve interpretDFD
• ktx: Improvements, cleanup and bug fixes
• cmake: Add CMake generator expression for output directory on Mac

Please complete the final review of this scope including the CTS.

[MarkCallow]

Looks good. I have several questions. A couple may result in you making code changes.

While reviewing this I spotted another feature of toktx that has not been brought forward to the new tools.

infiles prefixed with '@' are read as text files
listing actual file names to process with one file path per line. Paths
must be absolute or relative to the current directory when toktx is run.
If '@@' is used instead, paths must be absolute or relative to the location
of the list file.

Let's see if we get complaints from early users. When I added this to toktx it was not very difficult so I may try to add it myself, at some point in the future, with tests of course.