DRILL-6762: Fix dynamic UDFs versioning issue
1. Added UndefinedVersionDelegatingStore to serve as versioned wrapper for those stores that do not support versioning.
2. Aligned remote and local function registries version type. Type will be represented as int since ZK version is returned as int.
3. Added NOT_AVAILABLE and UNDEFINED versions to DataChangeVersion holder to indicate proper registry state.
4. Added additional trace logging.
5. Minor refactoring and clean up.
closes #1484
