API: Move AllowedReactions endpoint into GetGenneralUI endpoint + creat new swagger section settings (#11854)

* move Setting function into its own package

* swagger add&use new section "settings"

* move api AllowedReactions into general UI-Settings endpoint

* prepare TEST

* lint

routers/api/v1/settings/settings.go

@@ -0,0 +1,44 @@
+// 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 settings
+
+import (
+	"net/http"
+
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/setting"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// GetGeneralUISettings returns instance's global settings for ui
+func GetGeneralUISettings(ctx *context.APIContext) {
+	// swagger:operation GET /settings/ui settings getGeneralUISettings
+	// ---
+	// summary: Get instance's global settings for ui
+	// produces:
+	// - application/json
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/GeneralUISettings"
+	ctx.JSON(http.StatusOK, api.GeneralUISettings{
+		AllowedReactions: setting.UI.Reactions,
+	})
+}
+
+// GetGeneralRepoSettings returns instance's global settings for repositories
+func GetGeneralRepoSettings(ctx *context.APIContext) {
+	// swagger:operation GET /settings/repository settings getGeneralRepositorySettings
+	// ---
+	// summary: Get instance's global settings for repositories
+	// produces:
+	// - application/json
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/GeneralRepoSettings"
+	ctx.JSON(http.StatusOK, api.GeneralRepoSettings{
+		MirrorsDisabled: setting.Repository.DisableMirrors,
+		HTTPGitDisabled: setting.Repository.DisableHTTPGit,
+	})
+}