[MSD benchmark] feat: Sync app credentials between Cal.com & self-hosted platforms

[khaliqgant]

MSD benchmark PR recreated from Martian Code Review Bench.

Source PR: calcom#11059
Dataset: cal_dot_com
Original title: feat: Sync app credentials between Cal.com & self-hosted platforms

What does this PR do?

This PR allows self-hosters that have their own app store, to sync their user's 3rd party credentials with their instance of Cal.com. This allows their app store to be the source of truth for apps.

Fixes # (issue)

Requirement/Documentation

• If there is a requirement document, please, share it here.
• If there is ab UI/UX design document, please, share it here.

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How should this be tested?

• Set up the required .env variables that were added in the PR
• Hit the api/webhook/app-credential endpoint with the correct webhook secret and encrypted payload
• The new credentials should be created in the DB
• For the affected apps, force a refresh of the tokens. The endpoint they are hitting should simulate what a self-hoster would have made
• Force a refresh of the tokens but this time do not enable app credential syncing

Mandatory Tasks

• Make sure you have self-reviewed the code. A decent size PR without self-review might be rejected.

Checklist

• I haven't added tests that prove my fix is effective or that my feature works
• I haven't checked if new and existing unit tests pass locally with my changes