Style Icon, Index, Sign and Target when buffer is modified/pinned

[ymn64]

Is there a way to style the Icon, Index, Sign and Target depending on whether or not a buffer was modified?
I checked the doc and it seems that the only groups we can style are these:

BufferCurrent
BufferCurrentMod
BufferCurrentIcon
BufferCurrentIndex
BufferCurrentSign
BufferCurrentTarget

Would be great if we could have:

BufferCurrent
BufferCurrentMod
BufferCurrentIcon
BufferCurrentIconMod
BufferCurrentIndex
BufferCurrentIndexMod
BufferCurrentSign
BufferCurrentSignMod
BufferCurrentTarget
BufferCurrentTargetMod

[Iron-E]

Related: #539

[Iron-E]

See also #597 (comment)