feat: easily allow setting accordion and collapsible heights to arbitrary values

[Wombosvideo]

Description

Adds accordion-h-* and collapsible-h-* utilities to apply the content height CSS variable.

Allows either number values (in spacing units) or [*] any other value. This makes it possible to set the accordion height using

accordion-h-(--abc-accordion-content-height)

Fixes #36.

[Wombosvideo]

@Abdelrahmanaman
Instead of animate-collapsible-down-*, this PR adds the accordion-h-* and collapsible-h-* utilities. I've decided it would be better to have

• accordion-h-* to define the accordion content height
• collapsible-h-* to define the collapsible content height

instead of

• animate-accordion-down-*
• animate-accordion-up-*
• animate-collapsible-down-*
• animate-collapsible-up-*

because the content height is usually the same for both animations. I've also decided to add the -h- infix to leave open the possibility of adding horizontal animations in the future.

So, what this means for the example you gave in #36:

- animate-collapsible-down-[--kb-accordion-content-height]
+ accordion-h-(--kb-accordion-content-height)

(But you won't need this, because #37 adds first-level support for Kobalte variables. Future releases might deprecate these variables though)

I hope this implementation works for you and again, thanks for the suggestion!

[Wombosvideo]

@copilot Fix the merge conflicts

[Copilot]

@Wombosvideo I've opened a new pull request, #74, to work on those changes. Once the pull request is ready, I'll request review from you.