Add settings final clause

[limonyellow]

Adding SETTINGS final = 1 in the end of the query.

This is a useful ClickHouse feature to apply FINAL to all tables in the query:

"Automatically applies FINAL modifier to all tables in a query, to tables where FINAL is applicable, including joined tables and tables in sub-queries, and distributed tables."
https://clickhouse.com/docs/en/operations/settings/settings#final

A known issue when having joined tables in query.
ClickHouse/ClickHouse#8655

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Ensure PR doesn't contain untouched code reformatting: spaces, etc.
• Run flake8 and fix issues.
• Run pytest no tests failed. See https://clickhouse-sqlalchemy.readthedocs.io/en/latest/development.html.

Tests fix:
fix(parsing): change the way to quote db_url to fix the test broken by sqlalchemy 2.0.25

[xzkostyan]

There is more convenient way to define settings with execution_options: https://clickhouse-sqlalchemy.readthedocs.io/en/latest/features.html#execution-options. This separates settings a little bit from query itself.

But this only is not supported for HTTP-driver.

For HTTP-driver you must add SETTINGS in query. In Native settings are passed in special binary block.

There will be conflict in native driver if this PR will be merged. ClickHouse server will get two section setting -- in binary form and in text form.

There are two options:

1. we use .settings_final() only for HTTP and move these changes to HTTP-dialect (this covers only one setting final)
2. we implement passing settings with execution_options for HTTP (this will cover all settings). You don't need to write every server setting in driver, just form SETTINGS clause with strings concatenation here clickhouse_sqlalchemy.drivers.http.connector.Cursor.execute.

I'd recommend to implement the second option. It will be more flexible.

[limonyellow]

There is more convenient way to define settings with execution_options: https://clickhouse-sqlalchemy.readthedocs.io/en/latest/features.html#execution-options. This separates settings a little bit from query itself.

But this only is not supported for HTTP-driver.

For HTTP-driver you must add SETTINGS in query. In Native settings are passed in special binary block.

There will be conflict in native driver if this PR will be merged. ClickHouse server will get two section setting -- in binary form and in text form.

There are two options:

1. we use .settings_final() only for HTTP and move these changes to HTTP-dialect (this covers only one setting final)
2. we implement passing settings with execution_options for HTTP (this will cover all settings). You don't need to write every server setting in driver, just form SETTINGS clause with strings concatenation here clickhouse_sqlalchemy.drivers.http.connector.Cursor.execute.

I'd recommend to implement the second option. It will be more flexible.

Thanks for your insight. Let me know if this is what you meant.

[xzkostyan]

Yes, that's it.