Improved cache management

[DC-SWAT]

Perhaps it will be useful to someone and I will remove it from the DreamShell KOS patch.

[ianmicheal]

Do you have an example of using the improved cache functions for testing and use cases?

[DC-SWAT]

Do you have an example of using the improved cache functions for testing and use cases?

I did not do comparative testing, although probably should be.
In fact, I removed unnecessary operations in invalidate and flush a long time ago and they are works in DS and loaders without issues.
I did not find any documentation for these operations, and the authors of the Demul emulator told me that this is nonsense. For the rest, I added what was simply not enough for completeness here just for fun and use some in my code (purge and prefetch for example).

[DC-SWAT]

I removed allocation stuff because I remembered that I had issues with them and they were not used anywhere, so I decided not to create new issues here and removed it. Everything else is tested a years and not have any issues.