- some shenanigans rquired because of existing render fn

+ delete width Sass variables

- `noUpdateButton` requires a few per-width-type tweaks to get this working as before in prod, due to changed CSS delcaration order

- `isAutoRefreshOnly` is not correctly responding to width prop on prod, this fixes that

- flatten CSS where possible (in the case of `.euiFormControlLayout__childrenWrapper`'s border-radius it is sadly not possible)

- un-DRY prettyFormat CSS for now, DRY out with popover buttons later

- `!important` on `.euiSuperDatePicker__rangeInput` required to offset the CSS added by `fullWidth: true` on the form control layout

+ simplify `.euiDatePopoverButton` to inherit from the form wrapper instead of reusing the static variable

- use flex for compressed height instead of static form variables

- keep modifier classes for Kibana usage

- [opinionated cleanup/change] set background colors on the layout wrapper div instead of the button where possible

- reuse the CSS variable and form Emotion mixins where possible as well

+ fix test describe name