Feature/multiple enhancements

[steweg]

This PR includes multiple enhancements:

• Adding unlink function
• Adding LY_CTX_LEAFREF_EXTENDED context option
• Adding fraction_digits function for DLeaf
• Adding min/max_elements and uniques
• Reworked musts to use common function
• Enhancing Choice/Case options
• Extending pattern options
• Adding require_instance function
• Adding Type.derived_cdata function
• Adding insert_sibling function
• Adding only_node option to add_defaults

[samuel-gauthier]

Hi steweg,

Again, I will have a look, but...

same comment as for your other pull request, could you first conform to the project pull request guidelines?

• can you add unit tests to your commits?
• can you add proper commit logs, and check your commit titles, as described in the project guidelines?
• ideally, could you submit your pull requests by feature, instead of "multiple_enhancements", it will make it easier to split amongst the maintainers

Thanks,
Samuel

[steweg]

So far split to PR #84, #85, #86, #87. To be continued tomorrow

[steweg]

Split was completed, PR from #88, #89, #90, #91, #92, #93, #94, #95 and #96. Closing this PR