Show model diff in commit history

[MoritzWeber0]

It should be possible to see a model diff between commits in the commit history. A quick indication should be placed between commits in the history (number of added elements / diagrams, number of deleted elements / diagrams, number of changed elements / diagrams). When clicking on the diff indication, the detailed diff should be displayed.

Depends on https://github.com/DSD-DBS/capella-collab-manager/issues/1100.