[#50179803]
Move Msf::DBManager#migrate and the migrated attribute to
Msf::DBManager::Migration module to lower complexity of db_manager.rb
and in preparation for more migration related code on this branch.
[#49858419]
[SEERM #7958]
metasploit_data_models 0.14.3 relaxes the validation on
Mdm::Module::Detail#stance so it only needs to be in
Mdm::Module::Detail::STANCES if Mdm::Module::Detail#mtype is 'auxiliary'
or 'exploit' as framework only supplies a stance for those types when
using Mdm::Module::Detail.
[#47979793]
Multiple files define Msf::DBManager, but it's better to have one spec
for Msf::DBManager, so change spec structure to reflect module and class
hierarchy instead of file hierarchy of defining files.
Luke Imhoff