Add more checks when people use the flow to import jobs created manually

If we have a `staging` and `prod` env, the tool can be used so that jobs are created manually in `staging` and they can be promoted to `prod` using `import-jobs` and `plan`/`sync`.

But once some jobs have been promoted the `import-jobs` need to be filtering on the specific `staging` env id, otherwise changes done in `staging` to already moved to `prod` jobs are not getting reflected.

We should provider some warnings/errors and path to resolution when we realize that the `import-jobs` filter is missing the env filter.