I wasn't using any the features of ActiveSupport::Concern in
Msf::ModuleManager::Reloading, so remove the extend and just include it
as a regular module.
[Fixes#36737359]
Refactor Msf::ModuleManager into concerns so its easier to understand and
duplicate code can be made DRY. The refactoring also ensures that when
loading from directories, Fastlibs, or reloading, the wrapper module will
always be named so that activesupport/dependencies will function.
Luke Imhoff