Initial support for diagram diffing

[tortmayr]

Implement inital (client-side) support for diagram diffing with the process editor

• Update configuration defaults for p.json files so that files associated with a git scheme are opened with the text editor by default -> When opening a diff view for a p.json file from the git view the default text compare editor is openend by default
• Add an entry to the title bar of the text diff editor that allows reopening in the diagram compare view (use artificial uris with pdiff extension so that we can distinguish between files that are openend normally and in compare mode)
• Update process editor provider to handle .pdiff uris
  • Extract diff info (id, side, uri) from pdiff uris forward it to the webview
• Update the webview so that it attaches optionally present diff information to the args of the RequestModelAction

Missing:

• Server-side implementation. Currently the optional diff args are not evaluated and the server just openes the file normally

[ivy-lmu]

Hi @tortmayr, should this pr be reviewed already? I ask because it is in draft state.

[tortmayr]

@ivy-lmu Sorry for that. Yes the PR is ready for review.

[ivy-lmu]

hello @tortmayr

many thanks, the text-based comparison is already a great improvement. I'm just merging this default configuration change for now.
I have created a story for us so we will implement the server side to support the graphical comparison. So I'm leaving this PR until the server is ready.
I would say this request is solved for you, the rest of the work is on our side. Thanks!