Add configuration to disable ALL gremlins (useful for language-overrides)

[TheSench]

Description

This PR adds a gremlins.disabled configuration that allows all processing to be disabled. This setting is intended to be used with language-specific configurations so that gremlins can be completely ignored for files of a specific type.

Motivation and Context

This builds upon the language-specific configuration and allows ALL gremlins to be disabled for a given language without needing to manually override each of them individually.

How Has This Been Tested?

This has been tested using both manual and unit tests. I have tested turning the setting on to confirm that no gremlins are processed. Additionally, I have tested turning it on for a specific language, as well as turning it on globally, and then off for a specific language. In all cases, the expected behavior has been observed.

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.