Feat(dbt_cli): Set proper plan flags and also allow --empty and --environment

[erindru]

This PR:

• adds the --empty dbt option which maps to SQLMesh --skip-backfill (creates tables but doesnt write data to them).
• adds the --environment option to allow creating development VDE's. This is not a native dbt option but is a value-add of the SQLMesh engine.

In addition, this PR tightens up the plan flags to make SQLMesh more closely mimic dbt behaviour:

• All plans have --run and --ignore_cron set - except dev plans with no --select.
  This mimics the dbt behaviour of "always run up until right now" while falling back to the default SQLMesh behaviour for dev plans where the user has no interest in a particular set of models
• Dev plans set include_unmodifed=False to create dev environments with just the changes, create_from=prod,always_recreate_environment=True to ensure that dev environments are always based off the latest prod at the time the command is run and enable_preview=None to use default behaviour for dev previews.

Caveats:

• enable_preview=True is deliberately set even though this will cause changed dbt incremental models to be fully refreshed in dev environments. The assumption is that if the user is opting in to VDE, and this is a problem, then they may also consider opting in to SQLMesh incremental models
• --empty in dbt replaces existing tables with empty ones, but --skip-backfill just skips the backfill step and wont touch a table if it didnt already need to be backfilled. Therefore, this is a partial implementation of --empty until we have everything in place to enable --full-refresh semantics

[izeigerman]

should we add --env shortcut? or maybe make it an argument instead of an option? like we do for a plan? feel intuitive. Plus it doesn't look like dbt run has any arguments.

[erindru]

I think it would feel intuitive for a sqlmesh user, but people used to running dbt run are used to specifying a boatload of options, right?

dbt run --help reveals that the original command has no arguments, so the established practice appears to be to keep adding options

[erindru]

I did add --env as an alias

[izeigerman]

I don't know if we should even do this.

[erindru]

I couldnt get --skip-backfill to work without it in my example project?

[erindru]

After internal discussion, i've changed the ConfigError to a warning and stopped setting no_gaps to get around it.