Use `Metasploit::Concern.run(self)` in all models

[MSP-10037](https://jira.tor.rapid7.com/secure/RapidBoard.jspa?rapidView=84&view=detail&selectedIssue=MSP-10037)

Replace all usage of the explicit `ActiveSupport.run_load_hooks(<class_symbol>, self)` with the simpler `Metasploit::Concern.run(self)`.  Add `Metasploit::Concern.run(self)` to model classes that don't have it.  Importantly, make sure `MetasploitDataModels::Search::Visitor::*` classes support concerns so that metasploit-credential can add new search operators and operations that can be visited.  All models that use `Metasploit::Concern.run(self)` is specced with the `Metasploit::Concern.run` shared example to ensure it is hooked up correctly.