Add PR request link to GitHub ticket description (if available)

[exalate-issue-sync]

Business reason

Although our team works primarily in Jira, GitHub is our source of truth for our code and work. We need to ensure that if Jira goes away, we minimize any data loss or disruption in a transition back to GitHub. In addition, if public users go to GitHub versus a Jira ticket we want them to have all the same information available to them. This ticket will ensure that if a PR request is attached to a ticket in Jira, it is added to the body of the GitHub description.

Acceptance Criteria

Given a PR request is entered on a Jira ticket

When Exalate syncs with the associated GitHub ticket

Then the PR request link will be available at the bottom of the GitHub description.

QA Notes

null

DEV Notes

GitHub will only display the PR link if it exists.

On syncing back to Jira, the PR link will not show in the Jira description (this would cause duplicates of the PR link as syncing happened back and forth).

Design

null

See full ticket and images here: FECFILE-1818