Implement add and change definition ontology change request types

[jvendetti]

Implement support for add and change definition ontology change request types, which allow end users to propose the addition or modification of definitions associated with classes.

Syntactic examples:

• add definition 'This is a dummy description.' to FBbt:00000017
• change definition of FBbt:00000001 to 'member of species Drosophila melanogaster.'

References:

KGCL documentation pages:

https://incatools.github.io/kgcl/NewTextDefinition/ https://incatools.github.io/kgcl/TextDefinitionReplacement/

Formal grammar for add:

https://github.com/INCATools/kgcl/blob/e85763c7a8949345bba6f081307442974812acf9/src/kgcl_schema/grammar/kgcl.lark#L53C1-L53C15

Formal grammar for change:

https://github.com/INCATools/kgcl/blob/e85763c7a8949345bba6f081307442974812acf9/src/kgcl_schema/grammar/kgcl.lark#L51