Feat: Add spinner to Check Status button

[machikoyasuda]

closes #948

What this PR does

• Add Spinner to button if the button has a form.submitting_value.
• The Eligibility Verification form has a submitting_value (Checking), so the spinner shows up there. No other place in the current app has a form with a submitting_value.

Button with Spinner element

Spinner:

• 3px border width
• 16x16 total size
• 15px margin left from the text
• role="status" for a11y
• Comes from Bootstrap: https://getbootstrap.com/docs/5.1/components/spinners/

Button with Spinner:

• <button> with two <span>s
• One span for text, one span for spinner. (If these are in the same span, then the whole text would also rotate).

Testing

• Test all other buttons for height/size
• Test with keyboard
• A11y check: Does this new spinner affect a11y at all? If so how? How to mitigate?
• All other CTA buttons (besides Agency Index home page button) should have height 60px

[angela-tran]

LGTM

[thekaveman]

Wait why only for reCAPTCHA?

[machikoyasuda]

Wait why only for reCAPTCHA?

Oops that's false actually. I added the spinner divs to both branches of the code so it'll show up without reCaptcha too.

[machikoyasuda]

Shelving this for the time being until #1068 bug is resolved.

[thekaveman]

@machikoyasuda did you want someone to grab this one now that #1068 is merged?

[machikoyasuda]

@thekaveman yeah I was planning to - but you can do this ticket too! Whichever.