Allow RelatedID mapped fields to disallow pulls

Ok, labeling improved, and also a fix for the form behavior. Tests aren't here yet but let me know what you think of this UX language!

The value of the field, when checked, is true, not "match", which is preventing the code from running.

    handling:
      match: true

I'm including a patch to fix that.

Re-rolled patch for 5.0.3

Another re-roll against 5.0.4

Have you been using this patch in production?

The annoying thing with "disallow pull" is that it doesn't get automatically retried, ever.
So, even if the parent SFID does eventually get created, it won't trigger another pull attempt for the child record.

This is somewhat tangential, and shouldn't block this patch, but something to consider for folks that want to use this feature.

Are you talking about the queue item permanently being disallowed, or somehow the specific SF ID itself permanently getting disallowed? Because the latter is definitely a problem! The former doesn't seem so bad, although it would certainly be nice if it allowed some retries -- I can easily imagine cases where a retry would be likely to sync successfully. If that's the case, we could look at a different type of sync rejection. Maybe "postponePull"?

I'm talking about the situation where a subscriber might want to postpone pull.

The "disallowPull" method doesn't support this, outside of manually forcing another pull attempt.

There's no permanent disallow that i know of...