Migrate component data to ES modules

[colinrotherham]

This PR migrates our component data YAML into ES modules to:

1. Run type checks using TypeScript
2. Run code quality checks using ESLint
3. In future, import typed examples into tests without JSON conversion

This is important because we've accidentally missed things in the past:

• https://github.com/alphagov/govuk-frontend/issues/1903

But makes it a lot easier to add automated tests for:

• https://github.com/alphagov/govuk-frontend/issues/1139

Migration script

See branch component-migrator to convert YAML to ES modules via:

npm exec --workspace packages/govuk-frontend -- gulp fixtures

[colinrotherham]

Would appreciate your non-urgent thoughts on this one @36degrees

Using ES modules found some issues to fix so far:

1. Missing property { required } in Checkboxes nested options for conditional fields
2. Missing property { required } in Radios nested options for conditional fields
3. Missing property { description } in Summary list 'key.html' row parameter
4. Missing JSDoc type for example previewLayoutModifiers from #3808
5. Missing JSDoc type for example description

That's before we've picked up:

• https://github.com/alphagov/govuk-frontend/issues/1139

[colinrotherham]

Just rebasing since #2261 and tsc has caught another descrption typo in task-list.yaml

[Izabela-16]

@colinrotherham to add to the next show & tell

[github-actions[bot]]

:clipboard: Stats

File sizes

File	Size
dist/govuk-frontend-development.min.css	112.86 KiB
dist/govuk-frontend-development.min.js	38.53 KiB
packages/govuk-frontend/dist/govuk/all.bundle.js	78.63 KiB
packages/govuk-frontend/dist/govuk/all.bundle.mjs	73.89 KiB
packages/govuk-frontend/dist/govuk/all.mjs	3.86 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend-component.mjs	359 B
packages/govuk-frontend/dist/govuk/govuk-frontend.min.css	112.85 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend.min.js	38.51 KiB
packages/govuk-frontend/dist/govuk/i18n.mjs	5.38 KiB

Modules

File	Size (bundled)	Size (minified)
all.mjs	70.21 KiB	36.78 KiB
accordion.mjs	21.67 KiB	12.42 KiB
button.mjs	4.67 KiB	2.16 KiB
character-count.mjs	21.24 KiB	9.45 KiB
checkboxes.mjs	5.83 KiB	2.83 KiB
error-summary.mjs	6.57 KiB	2.92 KiB
exit-this-page.mjs	16.04 KiB	8.86 KiB
header.mjs	4.46 KiB	2.6 KiB
notification-banner.mjs	4.93 KiB	2.09 KiB
radios.mjs	4.83 KiB	2.38 KiB
skip-link.mjs	4.39 KiB	2.18 KiB
tabs.mjs	10.13 KiB	6.11 KiB

View stats and visualisations on the review app

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Action run for 238fcf69705a85c94d6fa09b1accd716336a99ca

[Izabela-16]

@colinrotherham Book a slot to talk about it at the next show & tell (sprint one).

[querkmachine]

Closing for housekeeping and because there doesn't seem to be much appetite to pursue this at the moment.