request: replace RichDisplay with PaginatedMessage

[kyranet]

Is your feature request related to a problem? Please describe.

RichDisplay is a Klasa-specific thing, but not only that, it's also flawed in many ways.

Describe the solution you'd like

@sapphire/discord.js-utilities has PaginatedMessage, which has all the features we need.

Describe alternatives you've considered

None.

Additional context

N/a.