Fix clickhouse proxy issue: hosts as query string DSN not parsed, also add alt_hosts support for DSN

[kokizzu]

Summary

some clickhouse proxy dsn use hosts (already on readme but not working) and/or alt_hosts, currently hosts not parsed into Addr, this causing settings considered a custom and those 2 key being injected when creating prepared statement, making prepared statements failing.

prepare: code: 115, message: Unknown setting alt_hosts
prepare: code: 115, message: Unknown setting hosts

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG