Revert "perf(dashboard): implement widget item api v2"

[st3iny]

This reverts commit 52feace.

I tested this locally and the dashboard widgets works like it did before (builtin viewer etc.).

[skjnldsv]

Status @st3iny ?
This works too #702 🤔

[susnux]

Can we somehow add a selector to the widget item API?
Meaning that it renders the widget with a class or ID assigned so we could hook into that.

So we could just use a very small script to add viewer support and still benefit from not needed to provide a full dashboard bundle

[skjnldsv]

@ChristophWurst @st3iny we're entering RC1, if this revert is important, it needs to get in asap! 👍

Otherwise, either close or change the milestone 🙏

[st3iny]

I rebased, resolved conflicts and tested again. I also fixed CI to finally make it green.

[st3iny]

@skjnldsv Your call regarding the merge. I'm not sure given that we had rc.1 already.

[Pytal]

master is now 30, moving to 30