Exclude views from get_table_names()

[aminghadersohi]

get_table_names() selected every row of information_schema.tables for the schema, so views were returned as tables in addition to being returned by get_view_names(). SQLAlchemy defines get_table_names() as base tables only; applications that list tables and views separately show each view twice.

Following review, the dialect now extends the upstream PostgreSQL reflection instead of replacing it (74df703, from @gordthompson):

• get_table_names() calls the upstream implementation (base tables only) and drops the multi_entries_to_ignore entries when no schema is requested. The pre-v2 SHOW TABLES branch and the has_table() override are removed, so has_table() is upstream's and still returns True for views, as SQLAlchemy 2.0 specifies.
• get_multi_foreign_keys() drops the multi_entries_to_ignore entries from the upstream result when no schema is requested.
• The schemas test requirement is open, so the suite's schema-qualified tests run. ComputedReflectionTest and the schema variant of test_metadata are skipped, and the dev requirements are refreshed.

664ebf6 passes the requested schema and the caller's postgresql_ignore_search_path through to the upstream calls. Previously they were hard-coded to None/False, so get_table_names(schema="test_schema") listed the default schema's tables. A CHANGES.md entry is under the unreleased 2.0.5 section.

Tests (test/test_introspection.py::TableNamesTest): test_get_table_names_excludes_views, test_has_table_includes_views, test_get_table_names_uses_requested_schema and test_get_foreign_keys_passes_ignore_search_path. The last two fail on 74df703 and pass on 664ebf6.

Full suite at 664ebf6 against CockroachDB latest-v26.3 (single node, test_schema/test_schema_2 created as in CI), SQLAlchemy 2.0.54, Python 3.10:

• psycopg2: 929 passed, 508 skipped
• asyncpg: 925 passed, 542 skipped
• psycopg: 929 passed, 508 skipped

For comparison, master with psycopg2 runs 731 passed, 705 skipped (the schema tests are not enabled there). flake8 (tox -e lint settings) is clean.

[gordthompson]

We can now extend SQLAlchemy's upstream code. Please review and merge

aminghadersohi#1

[aminghadersohi]

@gordthompson Thanks, that's much cleaner. I've brought your commit (74df703) into this branch unchanged. Running the suite against it turned up one problem: get_table_names() called super().get_table_names(connection, schema=None, **kw), so get_table_names(schema="test_schema") returned the public tables. The same pattern hard-coded postgresql_ignore_search_path=False in get_multi_foreign_keys(). 664ebf6 passes both through, and only drops the multi_entries_to_ignore names when no schema is requested, as get_multi_foreign_keys() already does. It also removes the except Exception: raise. Two tests in TableNamesTest cover this; they fail on 74df703 and pass now.

Full suite at 664ebf6 on CockroachDB v26.3 (psycopg2 / asyncpg / psycopg): 929 / 925 / 929 passed, no failures. The description is updated to match.

[gordthompson]

lgtm. Thanks!