chore: simplify storing and sending custom emoji's

- Using a map to store the CustomEmojis is unncessary, the values can be
derived by the key easily. We still need to know if a certain name is
custom emoji, so store the custom emojis in a `Set`.
- Instead of constructing a map in `window.config`, construct a `Set`
and reconstruct the value in `emoji.js`. This has the main benefit of
reducing the amount of text being sent for each request, which is quite
noticable if a Forgejo instance has many (>1000) custom emojis.
- Remove the default value of `CustomEmojisMap`, it will be constructed anyway.

modules/setting/ui.go

@@ -31,7 +31,7 @@ var UI = struct {
 	Reactions               []string
 	ReactionsLookup         container.Set[string] `ini:"-"`
 	CustomEmojis            []string
-	CustomEmojisMap         map[string]string `ini:"-"`
+	CustomEmojisLookup      container.Set[string] `ini:"-"`
 	SearchRepoDescription   bool
 	OnlyShowRelevantRepos   bool
 	ExploreDefaultSort      string `ini:"EXPLORE_PAGING_DEFAULT_SORT"`
@@ -87,7 +87,6 @@ var UI = struct {
 	Themes:                  []string{`forgejo-auto`, `forgejo-light`, `forgejo-dark`, `gitea-auto`, `gitea-light`, `gitea-dark`, `forgejo-auto-deuteranopia-protanopia`, `forgejo-light-deuteranopia-protanopia`, `forgejo-dark-deuteranopia-protanopia`, `forgejo-auto-tritanopia`, `forgejo-light-tritanopia`, `forgejo-dark-tritanopia`},
 	Reactions:               []string{`+1`, `-1`, `laugh`, `hooray`, `confused`, `heart`, `rocket`, `eyes`},
 	CustomEmojis:            []string{`git`, `gitea`, `codeberg`, `gitlab`, `github`, `gogs`, `forgejo`},
-	CustomEmojisMap:         map[string]string{"git": ":git:", "gitea": ":gitea:", "codeberg": ":codeberg:", "gitlab": ":gitlab:", "github": ":github:", "gogs": ":gogs:", "forgejo": ":forgejo:"},
 	ExploreDefaultSort:      "recentupdate",
 	PreferredTimestampTense: "mixed",
 
@@ -163,8 +162,6 @@ func loadUIFrom(rootCfg ConfigProvider) {
 	for _, reaction := range UI.Reactions {
 		UI.ReactionsLookup.Add(reaction)
 	}
-	UI.CustomEmojisMap = make(map[string]string)
-	for _, emoji := range UI.CustomEmojis {
-		UI.CustomEmojisMap[emoji] = ":" + emoji + ":"
-	}
+	UI.CustomEmojisLookup = make(container.Set[string])
+	UI.CustomEmojisLookup.AddMultiple(UI.CustomEmojis...)
 }