Add a builder for `CreateExternalCatalog` and `DropCatalog`

[alamb]

Is your feature request related to a problem or challenge?

• Follow on to Add an extension point to allow SQL based registration of external catalogs #25112

@pepijnve added new structs in for CREATE and DROP catalog.

As we mentioned here: https://github.com/apache/datafusion/pull/25112/changes/681f7c6cfbd1772f88756a368cb8cfcc5b715e9b..5e7f0d37305739e16a3b30a6dde5a520a2b8dbb2#r4066196509

Describe the solution you'd like

It would be nice to have a similar builder to the one for create table

Describe alternatives you've considered

No response

Additional context

No response