Add labels to BQ jobs created by sqlmesh

[benhinchley]

It would be great if the BigQuery jobs created by sqlmesh could have labels attached to them that describe

• If it was a run or a plan job
• The run or plan id
• The model in the bq job

It is handy to have this information, to understand the performance implications of various models, better understand slot utilisation per model/type, etc.

[VaggelisD]

Hey @benhinchley, this was actually on our roadmap starting with the PRs #4832 and #4861.

I didn't think of adding model specific information as this can be inferred by the query / DDL, but arguably it can be harder to spot with the versioning etc. Will look into this soon, thanks.