Added labeler workflow

[naman9271]

Fixes: #1240

This pull request introduces automated labeling for pull requests using GitHub Actions. The changes make it easier to categorize and track PRs by applying labels based on file paths and PR size.

Automated PR labeling:

• Added .github/labeler.yml to define label rules based on file paths, including categories like documentation, dependencies, frontend, backend, database, docker, CI/CD, API, security, tests, and configuration.
• Created .github/workflows/labeler.yml workflow to automatically apply labels to PRs using the defined rules whenever a PR is opened, synchronized, or reopened.

PR size labeling:

• Added a workflow step in .github/workflows/labeler.yml to label PRs by size (xs, s, m, l, xl) and optionally warn for extremely large PRs, ignoring certain files from size calculation.

[naman9271]

Hi @joaquinvanschoren , @janvanrijn please review when you get a chance - thanks