Adding extra error handling as already exists error occurs

[pritishpai]

Changes

CLI command create-catalogs-schemas sometimes fails if the catalog/schema already exists. The _get_missing_catalogs_schemas should help to avoid re-creating existing ones, but this seems like an edge case.

Linked issues

Resolves #1939

Functionality

• [ ] added relevant user documentation
• [ ] added new CLI command
• [ ] modified existing command: databricks labs ucx ...
• [ ] added a new workflow
• [ ] modified existing workflow: ...
• [ ] added a new table
• [ ] modified existing table: ...

Tests

• [x] manually tested
• [ ] added unit tests
• [ ] added integration tests
• [ ] verified on staging environment (screenshot attached)

[pritishpai]

[github-actions[bot]]

✅ 39/39 passed, 1 flaky, 2 skipped, 2h50m53s total

Flaky tests:

• 🤪 test_migrate_view (1m42.876s)

_{Running from acceptance #4697}