Move Bug Report Issue template to Issue Form

Summary:
Similary to the `release_blocker_form` we already have, this is migrating the
Bug report template to be an issue form.

Changelog:
[Internal] [Changed] - Move Bug Report Issue template to Issue Form

Reviewed By: lunaleaps

Differential Revision: D31729676

fbshipit-source-id: e78d5f4e8776fead17d45d340d98932cc41681e9