support INSERT INTO with SETTINGS

[senid231]

Version: 0.6.2

clickhouse guidelines suggests to use async_insert when inserting data 1 by 1, see https://clickhouse.com/docs/en/optimize/asynchronous-inserts

we need the possibility to send requests like

INSERT INTO YourTable SETTINGS async_insert=1, wait_for_async_insert=1 VALUES (...)

I've tried to prepend insert wth .settings(...) but it being ignored

>> ClickhouseActiverecord::VERSION
=> "0.6.2"
>> Clickhouse::SomeTable.settings(async_insert: 1, wait_for_async_insert: 1).create!(some_data: 123, timestamp: Time.current)
  Clickhouse Clickhouse::SomeTable Create (3.1ms)  INSERT INTO some_table (some_data, timestamp) VALUES (123, '2024-07-26 10:10:34')
=> #<Clickhouse::SomeTable:0x00007f36eecb3348 some_data: 123, timestamp: Fri, 26 Jul 2024 10:10:34.000000000 UTC +00:00>

as a workaround I've currently define these settings for ROLE but we should support such behaviour as well

[woodhull]

We're running a fork of the gem -- I'm not currently planning to turn this into a PR but we add a settings thread local for this:

daisychainapp@8baf903

Sharing in case that idea is useful for anyone else.