feat: add duckdb as DataSource - Fixes #14563 (#19317)

* + duckdb support

needs the forked version of [duckdb-engine](https://github.com/alitrack/duckdb_engine)

* Update duckdb.py

update  _time_grain_expressions

* removed superfluous get_all_datasource_names def in duckdb engine spec

* added exception handling for duckdb single-threaded RuntimeError

* fixed linter blips and other stylistic cleanup in duckdb.py

* one last round of linter tweaks in test_connection.py for duckdb support

Co-authored-by: Steven Lee <admin@alitrack.com>
Co-authored-by: Richard Whaling <richardwhaling@Richards-MacBook-Pro.local>

superset/databases/commands/test_connection.py

@@ -91,8 +91,9 @@ class TestConnectionDatabaseCommand(BaseCommand):
                         engine.dialect.do_ping,
                         args=(conn,),
                     )
-                except sqlite3.ProgrammingError:
+                except (sqlite3.ProgrammingError, RuntimeError):
                     # SQLite can't run on a separate thread, so ``func_timeout`` fails
+                    # RuntimeError catches the equivalent error from duckdb.
                     alive = engine.dialect.do_ping(conn)
                 except FunctionTimedOut as ex:
                     raise SupersetTimeoutException(