Replace issues/PRs management with GitHub policies

[fcabrera23]

Migrating the Issues/PR management to leverage the GitHub policies and [Microsft GitHub Policy Service](https://github.com/apps/microsoft-github-policy-service.

• Add new folder for GitHub policies
• Add a new file for PR management
• Add a new file for Issues management
• Remove old GitHub actions (opening PR/Issues and stale management)

Issues

• Mark issues as staled (add required labels) (7 days without conv)
• Close issues (14 days without interactions)
• Ping every 3 days if no comments are added and it's required by author
• Events
  ○ If a new comment is added, remove "no recent activity" and add "investigate"
  ○ If closed, remove tags "no recent activity"
  ○ If a comment is added after needs feedback, add the "Review" tag

PRs

• Mark PRs as staled (add required labels) (7 days without conv)
• Close PRs (14 days without interactions)
• Events
  ○ Comment when a new PR is opened
  ○ Add review label when new PR is opened
  ○ If review is added, add the "needs author feedback" tag
  ○ If changes are uploaded after needs feedback, remove that tag and add the "review" tag

[sebassem]

LGTM