Copy resultset data as xml, markdown and json

[MartinRyx]

A couple of versions ago the possibility to save resultsets to markdown, xml and json was added. That's great, but sometimes it would be quite handy to just be able to get the result in the clipboard instead of in a file.

Therefore I suggest the possibility to add buttons to copy resultsets as xml, json and markdown in addition to the Save to-features.

Describe alternatives you've considered
I could of course use the current functionality and first save the result to a file, and then copy from the file, but it's easier to get it to the clipboard right away.

Additional context
Current possibilities: