Checkboxes/radios - Add select all and allow under 'other' reveal

[boxadesign]

What is the context of this PR?

• Added "Select/Unselect all" to checkboxes
• Allow checkboxes and radios to "other" option
• Updated "other" reveal styling
• Added documetation

To do - Add unit tests for new scripts

How to review

Check examples, documentation

[codecov]

Codecov Report

Merging #1732 (8cf2fe6) into master (780336d) will increase coverage by 2.27%.
The diff coverage is 94.33%.

@@            Coverage Diff             @@
##           master    #1732      +/-   ##
==========================================
+ Coverage   94.11%   96.39%   +2.27%     
==========================================
  Files          66       65       -1     
  Lines        2668     2746      +78     
==========================================
+ Hits         2511     2647     +136     
+ Misses        157       99      -58     

Impacted Files	Coverage Δ
lib/rendering/create-nunjucks-environment.js	100.00% <ø> (+10.00%)	⬆️
...rc/components/checkboxes/checkboxes-with-reveal.js	100.00% <ø> (ø)
src/tests/spec/radios/radios.spec.js	92.30% <ø> (ø)
...rc/components/checkboxes/checkbox-with-fieldset.js	76.92% <76.92%> (ø)
...omponents/mutually-exclusive/mutually-exclusive.js	97.36% <83.33%> (+0.03%)	⬆️
...s/spec/table-of-contents/table-of-contents.spec.js	89.28% <89.28%> (ø)
src/components/table-of-contents/toc.js	92.85% <92.85%> (ø)
.../components/checkboxes/checkbox-with-autoselect.js	95.00% <95.00%> (ø)
...spec/checkboxes/checkboxes-with-autoselect.spec.js	100.00% <100.00%> (ø)
...kboxes/checkboxes-with-reveal-and-fieldset.spec.js	100.00% <100.00%> (ø)
... and 5 more

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[jrbarnes9]

• I think we should show realistic examples using the borderless variant (search filters etc), because we'd unlikely recommend this is used in questionnaires.

• When used in bordered, button should be ghost style...
  

• Alignment is a couple of pixels off
  

[jrbarnes9]

I think we should align the styling of legends/labels so they're always 18px bold, then align all nested legends and labels to 18px regular. So all nested input types (text, select, radio, checkboxes) will have the same style label/legend.

[jrbarnes9]

Apply these same content changes also to the radio component (where applicable)

[jrbarnes9]

New params need adding to macro options tables

[jrbarnes9]

• Selecting the nested radio labels in "Checkbox with revealed radios" doesn't check the input

[jrbarnes9]

I think we need to keep the legend "Choose preferred time of day" on this example.