Adjust NcSelect styling

[raimund-schluessler]

3 things:

• Style-wise it coukd look a bit more like the ActionMenu component, with the entries not expanding the whole width, but having a bit of margin and having a birder-radius Rounded select dropdown options #3818
• The contrast of the highlight seems to not be enough for accessibility, here we should also do it however we make the ActionMenu entry hover/focus accessible cc @JuliaKirschenheuter @Pytal
• Detail: The height of the co tainer should (if possible) always cut the list at ½ of the last entry, so that one entry is cut off and it is obvious to people that the list continues. :)

Originally posted by @jancborchardt in #3781 (review)

[Pytal]

• Style-wise it coukd look a bit more like the ActionMenu component, with the entries not expanding the whole width, but having a bit of margin and having a birder-radius

👍

• The contrast of the highlight seems to not be enough for accessibility, here we should also do it however we make the ActionMenu entry hover/focus accessible cc @JuliaKirschenheuter @Pytal

Currently uses the same color as NcActions items, --color-background-hover, though we can change it if you have any suggestions @jancborchardt?

For BITV a11y @michaelnissenbaum mentioned that only keyboard focus requires the minimum 3:1 contrast ratio and is addressed in #3711

• Detail: The height of the co tainer should (if possible) always cut the list at ½ of the last entry, so that one entry is cut off and it is obvious to people that the list continues. :)

Don't know why there is no scrollbar in the PR screenshot but on https://nextcloud-vue-components.netlify.app/#/Components/NcPickers?id=nctimezonepicker a scrollbar should appear

[jancborchardt]

For BITV a11y @michaelnissenbaum mentioned that only keyboard focus requires the minimum 3:1 contrast ratio and is addressed in #3711

Ah ok, then it's fine as is :)

@Pytal regarding scrollbar all good, I mean vertically the least entry should be cut in half. :) So then there is a clear visual indicator the list continues.