[RestCatalog] Implement unregister table in catalogs

[mkroll-db]

Is your feature request related to a problem or challenge?

Add catalog-level unregisterTable support introduced in #16400 to the REST catalog.

Unregister removes a table from the catalog without deleting its data or metadata files.
It returns a read-only table containing the last registered metadata. This can be used to register the table (with another catalog) again.

Describe the solution you'd like

The spec is clear and there is a reference implementation in java

The rough implementation will consists of:

• add unregister_table to catalog (defaults to unsupported)
• implement unregister_table in rest, sql and memory catalog
• add tests

Willingness to contribute

I can contribute to this feature independently