Personal preference I guess, but to me all of those commit messages are way too wordy. I'd probably have:
[PRJ-123] Refactor Foo out from Bar
[PRJ-123] Include Foo data in BazClient
[PRJ-456] Null-guard on Foo ID to avoid data loss
Bug introduced in commit deadbeef
And then in PRJ-456, I'd also have the comment about bug introduced in commit deadbeef, and link the two JIRAs if it was significant, or just mention it in a comment for a minor fix.
For me personally, nothing else in your commit messages adds value that can't be seen trivially from glancing at the changes.
For me personally, nothing else in your commit messages adds value that can't be seen trivially from glancing at the changes.