Handle commands in replies without changing message.content

[dnns01]

Pull request summary

At the moment, the message that is stored in a commands context will be changed. With this PR, the bug with replies will be fixed without changing the message itself.

Checklist

• [x] If code changes were made then they have been tested.
  • [ ] I have updated the documentation to reflect the changes.
  • [x] I have updated the changelog with a quick recap of my changes.
• [x] 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, ...)

[dnns01]

My last commit is after running through black, as I noticed the fail. So at that commit the lint check shoulg pass.