[Kernel] [UC] When/if applicable, update UCCatalogManagedClient codes to handle UC ratifying v0 commit

[scottsand-db]

Today, UC's catalogManaged commit API is not involved in table creation, as table creating uses unique staging tables and so commits are performed via filesystem writes directly to 000.json.

This causes a few interesting if statements / special cases in UCCatalogManagedClient code paths, as the UC::getCommits API will return maxRatifiedVersion=-1 for a table at version 0 (that has just been created).

If this is ever updated or changed, let's be sure to address all the relevant code paths.