Automatically set credits on security advisories based on contributors fields

In the cleanup at https://git.drupalcode.org/project/drupalorg/-/commit/54fdf4bd59067dbf47..., I brought back creating the hidden comments which should allow the names to transfer over. There’s one more followup at https://git.drupalcode.org/project/drupalorg/-/commit/ab02815e40efd30a56..., field_issue_credit should no longer be used anywhere.

This will get the names transferred over. Manually checking the boxes on the contribution record to actually grant the credit will be a necessary step. Leaving at needs review to double check this with the next advisory being published, and we might do a followup to automatically credit everyone for advisories.