fish_title is disabled for all Emacs terminal emulators #7122
Description
fish: version 3.1.0
OS: Debian rodete; NixOS 20.03
Fish disables the fish_title function if INSIDE_EMACS is set. However, Emacs has a variety of terminal emulators (for example term, shell and vterm) which all set different values for INSIDE_EMACS.
At least in vterm, title setting works fine. The check in this function should probably explicitly check for the terminal emulator that is considered broken (it seems to be term afaict), rather than disabling this by default in all of them.
The INSIDE_EMACS string for term and its derivatives looks like 26.3,term:0.96 (first is Emacs version, second is term version).