Draft: doc/Makefile: add stamp_error_codes to EXTRA_DIST, move more files to MAINTAINERCLEANFILES

• doc/Makefile: move more files to MAINTAINERCLEANFILES
• doc/Makefile: move stamp_* to MAINTAINERCLEANFILES... ... instead of DISTCLEANFILES, which should not include what's in the tarball.
• doc/Makefile: add stamp_error_codes to EXTRA_DIST

Fixes: #1797

Checklist

• Commits have Signed-off-by: with name/author being identical to the commit author
• Code modified for feature
• Test suite updated with functionality tests
• Test suite updated with negative tests
• Documentation updated / NEWS entry present (for non-trivial changes)

Reviewer's checklist:

• Any issues marked for closing are addressed
• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent and according to CONTRIBUTION.md
• This feature/change has adequate documentation added
• No obvious mistakes in the code