Add ADO PR autolinks based on merge message

[markjm]

Description

Closes #1486 Adds autolinks for merged Azure Devops PRs with default messages.

Checklist

• I have followed the guidelines in the Contributing document
• My changes follow the coding style of this project
• My changes build without any errors or warnings
• My changes have been formatted and linted
• My changes include any required corresponding changes to the documentation
• My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses

[markjm]

Hi @eamodio, thanks for maintaining this great plugin! I am looking to potentially start taking a look at helping out with #1170 . In digging around, I noticed this potentially simple change to start "getting my feet wet" in the repo.

Please let me know if you want to move forward with this change, thanks.

[M3kan1ac]

src/git/remotes/azure-devops.ts

[eamodio]

Thank you so much for your contribution!