Extend @CustomCmd decorator functionality

[r4isen1920]

77b2e0f

• This commit implements automatic registration of Enum-type parameter sets for custom commands by detecting enum types in mandatoryParameters and optionalParameters and invoking registerEnum as needed.
• Registered enum names are automatically de-duplicated.
• Updated test suite for custom command enum registration and de-duplication.
• Updated types to accomodate for stylish's custom command semantics.
• Updated documentation for CustomCmd.

8820072

• Add references to new @CustomCmd decorator

[r4isen1920]

I forgot to do this in #1 xD mb 🙏