Run all CE specs on EE codebase

Issue #2500 (closed) aims to make EE act like CE when there is no valid license provided.

So to ensure all CE feature remain working as expected, all CE specs should run without a license being activated.

Todo

• Recover all CE specs into the EE codebase
• Extract the EE changes made in the CE specs into EE-specific files in /ee/ sub-folders.
• Remove TestLicense.init from config.before(:all) in /spec/spec_helper.rb
• Only EE-specific specs can use TestLicense.init or stub_licensed_feautures to enable features

Related issues

#2335 (closed) and #2500 (closed)

cc @nick.thomas @reprazent @oswaldo @DouweM