EuiColorPicker inline and TS conversion

[thompsongl]

Summary

In preparation for the color stops component (#2344; see #2028 for discussion), EuiColorPicker needs to be able to render a standalone picker (no bound input or popover). This adds an inline boolean prop to support the required behavior.

Also, more of the EuiColorPicker dependencies have been converted to TS (all but one!), so I've made it TS as well.

Checklist

- [ ] Checked in dark mode
- [ ] Checked in mobile
- [ ] Checked in IE11 and Firefox

• Props have proper autodocs
• Added documentation examples
• Added or updated jest tests

- [ ] Checked for breaking changes and labeled appropriately
- [ ] Checked for accessibility including keyboard-only and screenreader modes

• A changelog entry exists and is marked appropriately

[chandlerprall]

Couple small nits, but otherwise LGTM!

[cchaos]

My only concern is having yet another boolean here. Is there anyway we can combine with mode or button since having a button with an inline version doesn't make any sense.

[thompsongl]

Combining with button makes some sense (like, passing false makes it inline). mode doesn't make sense, though, as its options are still valid with inline rendering (like, an inline swatch-less color picker).

I mostly went with the new boolean for consistency, because that's what EuiDatePicker has

[cchaos]

@snide And I have talked about it a lot lately and we're tend box ourselves in when we create new props that are straight booleans. Sometimes they're exclusive and sometimes they're not. It's almost better, if you don't see a logical place to add to a current prop, to create an enum style prop instead of boolean. Like for this one it could be display (our tried and true):

display: 'inline' | 'popover'

[ryankeairns]

LGTM. Tried it out, works as expected including keyboard navigation. It would be helpful to display the current hex value in this example, but that could be tackled later.