[EuiCombobox] allow for multiline options of different height

[mbondyra]

Is your feature request related to a problem? Please describe.
Although middle-truncation and auto-expansion alleviate most issues with long names, allowing multi-line will be a better approach in some circumstances. Our problem is specific to the users that have long field names in Kibana.

Quoting the customer:
“This is very frustrating, here: we have a huge list of fields. Some fields you cannot see here, because all the prefixes are the same. What I have to do is see the HTML code and copy the field.”
Right now the customer goes to Stack management and look at field names there — that's quite painful for them.

Describe the solution you'd like
It'd be good to allow not to truncate at all, but instead allow multi-line options.

Desired timeline
Kibana's 8.15 would be great.

[JasonStoltz]

@cee-chen Did we decide that this issue will be solve by #2841?

[cee-chen]

Yes, it will! Virtualization will be able to be disabled which will allow for height: auto type configurations. With caveats of course that it's a performance cost for high numbers of options.