[clang-tools-extra] [include-cleaner] rename enabled flags to `disable-*` (PR #132991)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> > If Insert or Remove is true, we should diagnose those as being deprecated and recommend using disable-insert or disable-remove instead.
> 
> `Insert` and `Remove` are true by default. Should it not be as false?

Oops, I meant "if they're used", so yes. :-)

> Also, the recommendation should be as regular `stdout` message, or is there a specific function for that?

`llvm::errs()` seems to be what the tool currently uses for diagnostics. There's no special helper function in the tool, so you can look at existing uses of `llvm::errs()` in `IncludeCleaner.cpp` for uses.

> > A release note should be added to clang-tools-extra/docs/ReleaseNotes.rst so users know about the change and new flags.
> 
> Is there a specific format for this note?

Something along the lines of:
```
Improvements to include-cleaner
-------------------------------
- Deprecated the ``-insert`` and ``-remove`` command line options, and added
  the ``-disable-remove`` and ``-disable-insert`` command line options as
  replacements. The previous command line options were confusing because they
  did not imply the default state of the option (which is inserts and removes
  being enabled). The new options are easier to understand the semantics of.
```

https://github.com/llvm/llvm-project/pull/132991