Feature: Add `data-testid` to important places for external custom e2e tests

[mhsdesign]

E2E testing neos can be hard sometimes and i lately relied much on css classes like:

[class^="_secondaryInspector"]
[class^="_markActiveNodeAsFocused--focusedNode"]
[class^="_leftSideBar__bottom"]

which is in my case fairly accurate as we dont rely on the exact hash but use starts with (^⁼)

but if you watch https://youtu.be/hzJPLKVarMw?t=1717 youll understand that its challenging ^^

with #3366 the above will not continue to work but one woul need to use the less specific: contains string *= as the css hash will be prepended to the classname

[Sebobo]

So you want to stop using ReactSelectors?

[mhsdesign]

no but for my own e2e tests (where I cannot use react selector because we dint enable this for production build)

[Sebobo]

Ah so the use case is e2e tests for plugins. OK cool!
Maybe you can adjust the title and description 😉