Fix File references

[#56005352]

Forgot to qualify File with ::File in
Metasploit::Model::Module::Ancestor#contents.
Eliminate need for ::File

[#56005352]

Make Metasploit::Model::File delegate to ::File, so I don't have to keep
qualifying method calls to methods not overriden in
Metasploit::Model::File.
Fix YARD

[#56005352]