Feature/new events

[0xRy4n]

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply.

• Bugfix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality not to work as expected).
• Documentation Update (if none of the other choices applies).

Proposed changes

This does the following:

1. Restructures the webhook code - HMAC verification, HTB account handler, etc.
2. Reworks much of the verification helper- we no longer assume an MP account and operate from the link event
3. Verify / identify cogs replaced to explain new process
4. Account and MP handlers added with new events
5. Linting rework and misc refactoring

Checklist

Put an x in the boxes that apply.

• I have read and followed the CONTRIBUTING.md
  doc.
• Lint and unit tests pass locally with my changes.
• I have added the necessary documentation (if appropriate).

Additional context

Add any other context or screenshots here.

[dimoschi]

I had the opportunity to review the code, even though the PR is still draft. Good job, some minor improvements. In general for the BaseHandler and the other handlers that implement it, I would consider making some methods private.

[dimoschi]

Is this really needed?

[0xRy4n]

This was an attempt to try to tame mypy but it is not really necessary no.

[dimoschi]

LGTM

[dimoschi]

@0xRy4n should we merge and release?

[dimoschi]

@0xRy4n & @0xEmma should we merge that? The PR looks good.

[0xEmma]

good on my side