Sort specs

MSP-11466
Spec methods from db_manager.rb

MSP-11466
Add modern --require to .rspec

MSP-11466

Modern rspec --init adds `--require spec_helper` to .rspec so that you
don't need to `require 'spec_helper` in all your specs.
Spec classes, constants and methods from lib/msf/db.rb

MSP-11466

Method specces only check that the method is defined as they only need
to catch deleted methods during the reorganization.
Split Msf::HostState into own file

MSP-11124
Fix indent in Msf::HostState

MSP-11124
Fix comment style in Msf::HostState

MSP-11124
Extract Msf::ServiceState

MSP-11124

Extract Msf::ServiceState from `lib/msf/core/db.rb` and put it into
`lib/msf/core/service_state.rb`.
Fix indentation in Msf::ServiceState

MSP-11124
Fix code style in Msf::ServiceState

MSP-11124
Extract Msf::DatabaseEvent

MSP-11124

Extract `Msf::DatabaseEvent` from `lib/msf/core/db.rb` into a more
conventional `lib/msf/core/database_event.rb`.
Fix indentation and whitespace in Msf::DatabaseEvent

MSP-11124
Fix code style

MSP-11124

Fix comment style and order methods.
Extract Msf::DBImportError

MSP-11124
Merge db.rb into db_manager.rb

MSP-11124

The class name is DBManager, so the correct file name is db_manager.rb
Extract Msf::DBManager::Sink

MSP-11124

Extract attributes and methods associated with the deprecated sink.
Extract Msf::DBManagerSink examples to shared example

MSP-11124
Move Msf::DBManager#sync to Msf::DBManager::Sink

MSP-11124

The comment on `#sync` says it's related to `sink`, so move it into its
Module.
Extract Msf::DBManager::Workspace

MSP-11124

Gather together all workspace related methods into
`Msf::DBManager::Workspace` and include it in `Msf::DBManager`.
Extract Msf::DBManager::Workspace examples to shared example

MSP-11124