[FEA] Automatically label new pull requests

[amahussein]

Is your feature request related to a problem? Please describe.

We manually apply labels to our pull requests to make it easier to navigate and understand the changes in each PR.
There is a subset of labels that very common to use and it will be nice to have them being added automatically:

1. core_tools: changes applied to the core scala module
2. user_tools: Changes related to the python wrapper
3. API-change: Changes that alter the output consumed by other external consumers (i.e. changing the API)
4. ...

Describe the solution you'd like

Consider adding a github action to automatically add new labels to the pull-requests. We can limit that to merges going into dev.

The "Pull Request Labeler" https://github.com/actions/labeler seems to be an easy option to use.