[SYCL][COMPAT] Memory Header cleanup

[Alcpz]

This PR cleanses up a the memory header to prepare for the next update:

• device_memory wrapper now accepts a queue argument (to be consistent with the rest of the memory calls)
• read_only usm property protected behind a feature macro
• removed syclcompat:: verbosity from some internal implementations
• Doxygen docs reviewed
• Variable names improved (M -> Mem, D -> Dim, Val -> Value)

[AidanBeltonS]

Refactor LGTM

[Alcpz]

@intel/llvm-gatekeepers PR ready for merging. Thanks!