R1:a34b769b4fea

Prevent creation of inline comments with mismatched changesetID / revisionPHID

Summary:
Ref T11092. With Quicksand (or, possibly, some as-yet-unknown non-Quicksand workflow) the client can get stuck with an out-of-date revision PHID.

We then save comments with a `revisionPHID` from one revision and a `changesetID` from a different one.

Detect and prevent this. This stops the workflow immediately when the use first clicks, so it should allow us to detect this issue if it has some other non-Quicksand…