tooling: add dapr-bot - assign issue functionality

[mikeee]

Description

Added:

• Simple rust app to process an issue comment (from the trigger context) and assign the issue to the commenting user located at .github/workflows/dapr-bot/*
• New workflow dapr-bot
• New workflow dapr-bot-test

The above has been tested on a live GitHub repo.

Usage:
To assign an issue to yourself, you can prefix the comment with /assign to trigger dapr-bot to assign the issue to yourself.
Example comment body:-

/assign

I have bandwidth to pick this up this week

Limitations:
The bot does not perform any validation on whether an issue is currently assigned to someone, the floor is open to any particular opinion. I think at this stage it would not make much sense to limit an issue to 1 assignee. Suppose a contributor drops off whilst assigned to an issue, another contributor should be able to assign themselves to an issue to indicate their intent to continue work on that issue.

TODOs (create issues after approval/merge):

• Will need further investigation with regards to the potential caching or saving of a build artifact to speed the run up.
• Docs issue to be created in dapr/docs on approval/merge

Issue reference

This PR will close #107

Checklist

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[mikeee]

Needs a symlink to the license file

[mikeee]

rename to main