[API] Expose allowed Reactions (#11735)

* [API] Expose allowed Reactions

* dont be in soutch a rush

* add TEST

* use ElementsMatch

Co-authored-by: Lauris BH <lauris@nix.lv>

routers/api/v1/misc/settings.go

@@ -0,0 +1,23 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package misc
+
+import (
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// SettingGetsAllowedReactions return allowed reactions
+func SettingGetsAllowedReactions(ctx *context.APIContext) {
+	// swagger:operation GET /settings/allowed_reactions miscellaneous getAllowedReactions
+	// ---
+	// summary: Returns string array of allowed reactions
+	// produces:
+	// - application/json
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/StringSlice"
+	ctx.JSON(200, setting.UI.Reactions)
+}