Added $mem for converting MB to lhex and vise-versa

[chrisdodgers]

Can also be used with the following aliases: $fbmem, $stolenmem, $unifiedmem, and $cursormem.

Usage example:
$stolenmem 26m

$fbmem 00009000

$mem 0x00000006

$cursormem 1MB

[chrisdodgers]

• Removed mib = [“mib”, “mb”, “m”] as it is unnecessarily redundant. Just checking for if ”m” exists in the input value serves the same expected results determining if dealing with MiB input .
• Removed is_lhex. Kind of pointless as if the input value doesn’t fall under is_mib, just assume its lhex. Any bad input values resulting in an error would just be caught in the try/except.
• Removed the unnecessary string comparisons of from_type and to_type. Conversion logic for MiB -> lhex happens now in if is_mib, and else we do lhex -> MiB.
• Removed the regex handling in num to strip mib from the input value. Instead, just simply only storing 0-9 and . in the float and ignoring any other character that may be in the input value.
• Cleaned up the calculation for bytes_val by using num * 1024 ** 2 instead of num * 1024 *1024. (And cleaned this up likewise in mib_val).
• Removed hex_val and instead directly feeding bytes_val to _convert_value using decimal to lhex32. Using lhex32 instead of originally lhex replaces the previous need of pre-formatting to get proper padding.
• Removed the use of Nullify. The output of _convert_value() is already sanitized and can be fed directly to the ctx. Also it is not needed in the particular response in except Exception.

Huge credit and thanks to @corpnewt for these clean up suggestions and for pointing out things I originally overlooked.