Add getMax to fetch maximum/native resolution

[ghostwriternr]

Changes

Fetch max supported mode for each monitor

Newer versions of MacOS use a scaling factor (like 2x, which is the
default for newer MacBooks), leading to the default mode being half the
native resolution of the display. In such cases, it would be desirable
to fetch the maximum resolution supported by the display (native
resolution).

Add a getMax option to fetch this information.

Avoid de-reference in _compareCFDisplayModes

Currently, the _compareCFDisplayModes method uses CGDisplayModeRef*
as the first and second parameters, in alignment with the
CFComparatorFunction type alias declaration expecting an
UnsafeRawPointer. But CGDisplayModeRef is already a pointer to
CGDisplayMode and doesn't need a reference again to work as a
comparator. Doing so also introduces extra referencing and dereferencing
that can be avoided.

[ghostwriternr]

Quick note: I have little to no experience with C, much less Apple Dev tools. I have been using the neofetch script for years, which depends on this library, and has lately been showing incorrect resolutions due to Apple's latest changes. So rather than adding workarounds, I wanted to add support for this at the source, if possible.

Please do let me know if this could have been done in a better way, as well as major code improvements.

[ghostwriternr]

@jhford gentle nudge to review when you can : )

[ghostwriternr]

Bump.