Refactor: libcrmcommon: Clean up add_schema_by_version()
The main change is to drop transform_expected argument, and simply call
add_schema() directly if that argument would have been false.
Other changes include:
- Rename xslt variable to path
- Rename s variable to sb
- Reduce variable scopes
- Improve comments
- Drop redundant ".xsl" from log messages (path must already contain it)
This will simplify further in upcoming commits.
Signed-off-by: Reid Wahl <nrwahl@protonmail.com>