fix(card): [EMU-7042] Add falsy value option for actionIcon and fix actionable card sizes

[diogomateus]

What this PR does

This PR fixes:

• card action action which now allows to use falsy values to not render it (e.g. <Card actionIcon={null} />)
• fixes card sizes that were differently if it was an action card, with and without action icon.

Solves:
EMU-7042

Before:

After:

How to test?

Run storybook and check the Card stories.

Checklist:

• I reviewed my own code
• The changes align with the designs I received
  Or give a reason why this does not apply:
• I have attached screenshot(s), video(s) or gif(s) showing that the solution is working as expected
  Or give a reason why this does not apply:
• I have updated the task(s) status on Linear
• All new media is optimized (images, gifs, videos)

Browser support

My code works in the following browsers:

• Firefox
• Chrome
• Safari
• Edge

[a-maffei]

I applied actionIcon={null} and compared card sizes with and without the action icon - everything works as described 👍

[talo242]

Thanks for this @diogomateus! 💅🏼