[#641] Add unresolved TODOs checks to danger

Description

Problem: Sometimes we left such TODOs, which either depend on the current MR or other tasks or MRs:

-- TODO replace it with X after [#9999] is finished

-- TODO (this MR) uncomment line below

but their resolving isn't checking anywhere and can be missed.

Solution: Added appropriate check to danger. It gets current issue id (both gitlab and YT) from MR body (namely, from "Resolves #X" line) and looking for TODOs related to this issue and current MR in repository. If some MR doesn't resolve any issue, then only those TODOs related to the MR itself are searched for.

Related issue(s)

Resolves #641 (closed)

✅ Checklist for your Merge Request

Related changes (conditional)

• Tests (see short guidelines)

  • If I added new functionality, I added tests covering it.
  • If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

• Documentation

  • I checked whether I should update the docs and did so if necessary:
    • Root README and other README.md files
    • Haddock
    • docs/
  • I updated changelog files of all affected packages released to Hackage if my changes are externally visible.

Stylistic guide (mandatory)

• My commits comply with the following policy.
• My code complies with the style guide.