Optionally show notebook tag and title on each card

[virtulis]

Pretty useful to arrange cards across all projects at once.

Not sure if I had to make a separate context and config dialog or if there was a simpler way :)

The API docs say "icon" is "text" while it seems to be either a "" or a JSON object, not sure if it can be something else so I put in a try-catch just in case.

[PackElend]

Thx for the pr 🙂
Can you share a screenshot of the where to set the option?

[virtulis]

I added an icon in the top right corner - you'll need to "add" a "rule" in that dialog.

Or you can just add it to the display config in markdown, like:

```kanban
filters:
  rootNotebookPath: /
columns:
  - name: Backlog
    backlog: true
  - name: Work in progress
    tag: wip
  - name: Finished
    tag: done
display:
  showNotebookTag: true
```

[PackElend]

@virtulis we are still searching for a new maintainer but as you familiar (a bit) with the codebase of the plug-in would are ok with checking the other PRs.
I can't call myself experienced enough, but if some of the others would check each other's PRs, it can be said that the code is safe, so I merge it.
At least there would be some progress
thx

[mhelleboid]

The code works as described, and the test case has passed.

This would be good to modify the main README.md to indicate this feature to users (even if the "eye/display" icon can help)

[mhelleboid]

This feature is so nice, that maybe it could be activated by default, with an option to desactivate it (instead of the opposite)