feat: Flag new class of ungrammatical uses of "of which"

I'd never heard or seen this until the past few months. But now I'm hearing it in YouTube videos and reading it in code comments, etc.

It's more than one exact error. They all involve "which" combined with one or more prepositions. Either there's "of which" when there should just be "which" or there's "of which" with another preposition after the noun phrase that should be in the spot "of" is, before the which.

Some have factors in their context which may not fit fixed rules but revolve around **of which**.

I'll add examples found in the wild as my attempts to invent them won't be realistic:
- it is forced to read in fixed sized chunks and then cache any residual unused input frames, **those of which** will be processed at a later stage.
→ ... input frames **which** will be processed at a later date

No files, tests, or entry points are named. Start by reviewing the supplied “of which” examples and the surrounding issue discussion to determine the supported grammatical patterns and their boundaries. Done means the agreed class of ungrammatical uses is detected without incorrectly flagging valid uses, with representative examples covered by tests.

Written by the indexing model from the issue text.