Use request.CTX instead of *request.Context (#24877)

* Use request.CTX instead of *request.Context

* Fix tests

server/channels/app/slashcommands/command_groupmsg.go

@@ -39,7 +39,7 @@ func (*groupmsgProvider) GetCommand(a *app.App, T i18n.TranslateFunc) *model.Com
 	}
 }
 
-func (*groupmsgProvider) DoCommand(a *app.App, c *request.Context, args *model.CommandArgs, message string) *model.CommandResponse {
+func (*groupmsgProvider) DoCommand(a *app.App, c request.CTX, args *model.CommandArgs, message string) *model.CommandResponse {
 	targetUsers := map[string]*model.User{}
 	targetUsersSlice := []string{args.UserId}
 	invalidUsernames := []string{}