The package provides liblibmusicxml.so (because reasons).
Consolidate cmake calls to adhere to packaging guideliens.

devtools 20230105-1 enables the debug option by default.

A follow-up commit will remove debug from alongside other options.

Remove unnecessary quotes and curly braces.
Simplify calls to cmake and apply cmake package guidelines.
Move all docs to doc dir.

Upgrading to 3.17. Updating maintainer info. Adding all direct library dependencies. Removing empty prepare(). Removing unreqired fix for moving documents.

Rebuilding, as upstream retagged a version and introduced a soname change (https://github.com/grame-cncm/libmusicxml/issues/36). Adding libmusicxml2.so to provides.