Add abstract `createCopy` method in `SelectMenu`

[Kaktushose]

Pull Request Etiquette

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Changes

• [x] Internal code
• [ ] Library interface (affecting end-user code)
• [ ] Documentation
• [ ] Other: _____

Closes Issue: NaN

Description

Adds an abstract createCopy method in the SelectMenu interface. This allows to create a copy of a SelectMenu without knowing the actual type