Implement MapPhysicalMemory/UnmapPhysicalMemory

This implements svcMapPhysicalMemory/svcUnmapPhysicalMemory for Yuzu,
which can be used to map memory at a desired address by games since
3.0.0.

It also properly parses SystemResourceSize from NPDM, and makes
information available via svcGetInfo.

This is needed for games like Super Smash Bros. and Diablo 3 -- this
PR's implementation does not run into the "ASCII reads" issue mentioned
in the comments of #2626, which was caused by the following bugs in
Yuzu's memory management that this PR also addresses:
* Yuzu's memory coalescing does not properly merge blocks. This results
  in a polluted address space/svcQueryMemory results that would be
  impossible to replicate on hardware, which can lead to game code making
  the wrong assumptions about memory layout.
  * This implements better merging for AllocatedMemoryBlocks.
* Yuzu's implementation of svcMirrorMemory unprotected the entire
  virtual memory range containing the range being mirrored. This could
  lead to games attempting to map data at that unprotected
  range/attempting to access that range after yuzu improperly unmapped
  it.
  * This PR fixes it by simply calling ReprotectRange instead of
    Reprotect.