Feat!: Tag queries with their plan id

[VaggelisD]

This PR enhances the SnapshotEvaluator such that it appends a comment containing the plan_id at each query generated under it.

This can help associate historical queries with a plan after the fact and paves the way for tagging queries with labels/tags in engines like BigQuery and Snowflake.

[georgesittas]

Nice work, looks good. Is the next step to manually intercept the adapter instantiations elsewhere (e.g., unit tests), to ensure the IDs are properly generated in their execute as well?

[VaggelisD]

Is the next step to manually intercept the adapter instantiations elsewhere (e.g., unit tests), to ensure the IDs are properly generated in their execute as well?

That's right, the first iteration covers only the snapshot evaluator for now. Subsequent iterations can also include the engine adapters in state_sync, testing_connection etc.

EDIT: Actually, intercepting the unit test queries may not be straightforward because they've ran well before the plan id has been generated.