upgpkg: discord 0.0.54-2: refactor, fix autostart, add deps, use wayland

* Slightly refactor PKGBUILD
* Fix autostart desktop file
* Add optional dependency used in official arch package
* Include patch to allow Krisp noise suppression support
* Add install file to inform user about this change
* Use Wayland instead of Xwayland in a Wayland session by setting
  Electron flag `ozone-platform-hint` to auto (default is X11)

discord_arch_electron.install

@@ -0,0 +1,19 @@
+post_upgrade() {
+	# return if old package version is greater than or equal to 0.0.54-2...
+	(( $(vercmp $2 '0.0.54-2') >= 0 )) && return
+
+	cat <<EOF
+==> In order to patch Krisp noise suppression support set 'PATCH_KRISP=true'
+    in '~/.config/discord.conf' in addition to having 'rizin' installed.
+EOF
+}
+
+post_install() {
+	cat <<EOF
+==> For Krisp noise suppression support consider installing 'rizin' and
+    setting 'PATCH_KRISP=true' in '~/.config/discord.conf'. Restart your
+    Discord client afterwards to apply the patch.
+==> In case of performance problems consider setting additional flags
+    in '~/.config/discord-flags.conf'.
+EOF
+}