Fixes essentially a shadowing issue.

Addresses review feedback

Co-authored-by: Morph <39850852+Morph1984@users.noreply.github.com>

Allows for 6GB and 8GB layouts to be selected.

Co-authored-by: Morph <39850852+Morph1984@users.noreply.github.com>

Not sure how I missed this earlier, but these vectors can be constructed
using the type of the enum.

settings_common: Remove unused optional

Reduces some ugliness in frontend code.

Suggests to a frontend how to represent each setting.

This gets rid of some repeated code and sets us up to send more
information to the new widget.

Currently unused, but I don't want to start headaches when someone
decides to use it the first time.

Renames enum values to conform to naming convention.

The new enum macros don't support setting values directly.
For LastAA and LastFilter, this means we need a simpler approach to loop
around the toggle in the frontend...

This lets us define an enum and all the textual representations
of its values in one swing. All for the price of some ugly macros.

Clang versions < 15 have compile issues with explicit instantiation.
Disable it for these versions.

Fixes -Wshadow, -Wdeprecated, and catch by copy rather than by ref.