CLI (runtime?): report better errors when adaptors aren't installed

A common problem is to try and run a job - particularly a workflow - when adaptors aren't installed to the repo.

Right now the error you get isn't very good or very useful. We can do better.

 throw new Error(`Failed to load module “${specifier}“`);
        ^
Error: Failed to load module “@openfn/language-postgresql”

This raises the idea of prevalidating adaptors in the CLI before running the job - which I abandoned because it was getting a bit too complex.

But maybe if -i isn't provided and the repo doesn't provide a matching version, we can raise an error

Start at the CLI path that runs a job or workflow and follows adaptor module loading, especially when -i is absent. Reproduce the missing @openfn/language-postgresql error, then determine the expected message for a repo without a matching adaptor version; done means the CLI reports a useful, actionable error before or instead of the current module-load failure.