refactor(tests): rewrite dump tests to compare via flight sql queries

[shiyasmohd]

Summary

• Replace SnapshotContext-based comparison with direct Flight SQL query comparison.
• Remove unused SnapshotContext fixture and snapshot helper functions.
• Refresh base_rpc snapshot data.

Note:
Before this PR we were comparing same data in assert for it_dump.rs. Since now we have physical table revision management APIs via admin-api after restoring snapshot, we deactivate those tables and then deploy new dataset. Through this we are now dumping fresh data. During testing, found a bug on base_rpc snapshot. request_hash field in blocks table was not found in snapshot. Updated the base_rpc snapshot with fresh data now. Also found outdated data on eth_firehose & base_firehose datasets. Updated them with new snapshots too.

Closes #1662

[LNSD]

LGTM ✅

Only one minor detail.