[1142] PR notifications for projects

[surajkumar]

Still in progress

About this PR

Introduces 1 slash command /link-gh-project and a new routine.

/link-gh-project: This command is used to link a project posted in #projects to a GitHub repository. The term "linking" is used lighly because under the hood it's just saving the following details to the database:

• channel ID
• repository owner name
• repository name There are checks done to ensure the repo is accessible before linking.

ProjectPRNotifierRoutine This routine runs on a 10 minute schedule. It goes over all the projects and checks for any PRs that have been created since the last poll time and then sends the notification to discord.

This PR features verbose logging at various levels. Don't complain, they are there so we can follow the entire logic in the event of a bug/error. It's useful debugging. I won't change this.

closes #1142