Merge 3.0 into main

[EvieePy]

Description

Version 3 is the new major version of TwitchIO.

Some things we are currently aware of that do need attending to mostly relate to documentation, however we feel it is currently in a well enough state to open to beta.

E.g.:

• Migrating Guide needs completing.
• Events Reference needs completing.
• Guides and Examples need completing.

TwitchIO 3.0dev has been in an Alpha stage for close to three months and matured enough since that stage to warrant broader testing and use.

Resolves #438
Resolves #419
Closes #404
Closes #394
Resolves #388
Resolves #355
Resolves #242
Resolves #216
Resolves #450
Closes #460
Resolves #466
Closes #473
Resolves #359
Resolves #416
Closes #461
Resolves #463
Resolves #470
Resolves #475

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
  • I have updated the changelog with a quick recap of my changes.
• 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, ...)
• I have read and agree to the Developer Certificate of Origin for this contribution