Add ability to use cutom table names

[akoevroman]

Is your feature request related to a problem? Please describe. Currently, it is hard to use custom table names for the User and Role tables, for example when you are using Orchid as an admin panel with custom user tables, which are different from the main app.

It may seem that you can easily extend the User model with AppServiceProvider configuration but not: The main drawback is that you need also to change two Traits for the pivot role_user table.

Describe the solution you'd like Would be great to have configuration values for table names or the ability somehow to change the pivotable table name.