Batch mode

[#60477624]

MetasploitDataModels::Batch.batch { } will turn off uniqueness
validations for faster batch processing of the module cache.
factory_girl 4.3.0 compatibility

[#60433512]

`method` is a defined method on the definition proxy in factory_girl
4.3.0, so need to call add_attribute directly instead of using
method_missing behavior to define attributes called `method`.
Fix specs

[#60477624]
Merge pull request #41 from rapid7/bug/metasploit-framework-module-cache-prefetch-time

MSP-8948 #land