ext.pages updates/changes

[krittick]

Summary

Provides the following enhancements/feature requests to ext.pages:

• Rework of how buttons are added/removed to allow for greater flexibility
• Option to loop the paginator when reaching the end
• Ability to include multiple embeds in a single page
• Option to switch between groups of pages with a select menu
• Option to send the paginated message to a different target than the context where it was invoked from
• Rework send() and respond() to be more consistent with other library usages of those methods
• More usage examples

Note: This PR is a breaking change for the existing ext.pages module as it completely reworks a large portion of how buttons are handled.

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, typehinting, examples, ...)

[Dorukyum]

Looks good to me

[Lulalaby]

LGTM, not approving tho.
@Middledot please review

[ChickenDevs]

Also looks good here, still not fully approving yet though.

[Middledot]

looks good here