User Display Role Should be More Dynamic

[alex-ye]

Hi , I think the title is clear , the current user display role function doesn't display the roles like "spam" , and if you add more user roles by yourself you must filter the bbp_get_user_display_role() to display it publicly .

[johnjamesjacoby]

(In [4793]) Introduce bbp_get_dynamic_role_name() to handle getting a translated role name from the dynamic roles array. Use this to return a more accurate display role in bbp_get_user_display_role(). Hat tip alex-ye. Fixes #2248.