Add columns for table system.storage_policies

[lzydmxy]

Changelog category (leave one):

• Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

add columns perform_ttl_move_on_insert, load_balancing for table system.storage_policies, modify column volume_type type to Enum8.

[kssenii]

Could you please update the integration test test_multiple_disks/test.py::test_system_tables? It fails now
See https://s3.amazonaws.com/clickhouse-test-reports/48167/2232d5ad14513273e9dff7fe096caac140c398f1/integration_tests__asan__[4/6].html
If here you tap on integration_run_parallel3_0.log
you'll see

>       assert sorted(clickhouse_policies_data, key=key) == sorted(
            expected_policies_data, key=key
        )
E       AssertionError: assert 

Or you can make some of the changed fields back to String type to fix the test, I am personally not sure if using Enum is better here.

[lzydmxy]

Could you please update the integration test test_multiple_disks/test.py::test_system_tables?

Surely, and i will check other system.storage_policies useges in tests.

Or you can make some of the changed fields back to String type to fix the test, I am personally not sure if using Enum is better here.

I think using Enum is better for column volume_type, but i can change fields back to String type if you want.

[lzydmxy]

@kssenii Please review when you have a chance : )