Rogerhu improvements + Update issue keys

@rogerhu has done some excellent work which has been sitting in a PR on the main repo (https://github.com/thurloat/sentry-jira/pull/61) which we have been using happily in production. 

This PR also includes some changes that we made at MapMyFitness. Our workflow involves creating a ticket in a single JIRA project and then moving that ticket to one of a number of projects depending on what team will be fixing it. This change (5fb5e1b37341a5591a863830b27c538c1fc1795d) adds two links to the sidebar of the group detail page: one is a link to the JIRA issue, the other is a link that refetches the ticket information and updates the tag to reflect the new ticket issue key.