community/nerd-fonts: restore nerd fonts & upgrade to 3.1.1

Upstream nerd fonts ships:

• The nerd font symbols themselves.
• Several other fonts patched to include nerd font symbols.

The upgrade to upgrade to 2.3.3 was a full rewrite of this package, and dropped font-nerd-fonts-symbols; only patched versions of other fonts were retained. I believe this drop was done inadvertently during the refactor and not intentional.

Previously the nerd font symbols font came in two variants, font-nerd-fonts-symbols-2048em and font-nerd-fonts-symbols-1000em. As of v3.0.0, both variants have been merged by upstream into one. This commit re-introduces nerd font symbols as "font-nerd-fonts-symbols".

A replaces= directive is also included so that existing installations of the previous version will upgrade to this one (upstream has dropped the two variations that previously existed and now only ships a single one).

Also install the fontconfig file provided by upstream.

Fixes: !38362 (merged)