Decouple schema fetch queries from server-side timeouts

[dkropachev]

Details

If the user set server-side timeouts, or service level timeouts, this impacts schema fetches. The timeout can be too low to allow a schema fetch when the schema is very large.

Instead, qualify schema (and other metadata) fetches with USING TIMEOUT (with a high and configurable default) so schema fetches work regardless of timeout tuning.

Core issue: scylladb/scylladb#18471

Limitations

1. USING TIMEOUT is not supported by cassandra and support by all major scylla versions, so it is safe to assume it is supported by seeing scylla-specific metadata.
2. Minimal supported scale is ms, so statement suffix should look like this: USING TIMEOUT {timeout_in_ms} ms

Requirements

1. Timeout should be configurable and default should be 2s
2. 0 signals that feature is disabled

[mykaul]

We've implemented it in all other drivers, we see customers hit by this in the field - I don't understand why it's a 1.1.0 content and not sooner.

CC @roydahan

[Lorak-mmk]

We have a deadline for 1.0 and we won't be able to keep it if we add more stuff there.
In contrary to the changes that we will include in 1.0, this one can actually be implemented in 1.1.

[mykaul]

We have a deadline for 1.0 and we won't be able to keep it if we add more stuff there. In contrary to the changes that we will include in 1.0, this one can actually be implemented in 1.1.

Create a release before 1.0 with that fix. A mythical '1.0' cannot have a priority over real customer issues.

[roydahan]

This is a new feature, not going to be merged into 0.15.
Nice to have for 1.0.0, only if it makes it in time.