Extract a CheckboxInput component from onboarding flow

[selfcontained]

Description

Extracts the checkbox input used in the onboarding flow to a CheckboxInput component and also creates a CheckboxInputField that wraps a list of checkboxes in the same styling as other input type components do. This should allow us to use it as a field w/ a list of checkboxes, like the onboarding flow, or as a standalone checkbox like we do in other places.

<CheckboxInputField label="My Label">
  <CheckboxInput value="1" label="First Option" checked={true} onChange={handler} />
  <CheckboxInput value="2" label="Second Option" checked={true} onChange={handler} />
  <CheckboxInput value="3" label="Third Option" checked={true} onChange={handler} />
</CheckboxInputField>

Other places in our UI use a <CheckBox/> component that I've referred to for some of the styles here, but plan on replacing those with this <CheckboxInput/> component for consistency. There's a few things to figure out w/ some of our font sizing, weights, and colors for form-related components, so I'll leave that as a separate task.

Related Issue(s)

Relates to #16511

How to test

• Run through the onboarding flow, and step 3 will have the checkboxes that use this component.
• https://bmh-checkb5001557072.preview.gitpod-dev.com/workspaces?onboarding=force

Release Notes

NONE

Documentation

Build Options:

• /werft with-github-actions
  Experimental feature to run the build with GitHub Actions (and not in Werft).
• leeway-no-cache
  leeway-target=components:all
• /werft no-test
  Run Leeway with --dont-test

Publish Options

• /werft publish-to-npm
• /werft publish-to-jb-marketplace

Installer Options

• with-ee-license
• with-slow-database
• with-dedicated-emulation
• with-ws-manager-mk2
• workspace-feature-flags
  Add desired feature flags to the end of the line above, space separated

Preview Environment Options:

• /werft with-local-preview
  If enabled this will build install/preview
• /werft with-preview
• /werft with-large-vm
• /werft with-gce-vm
  If enabled this will create the environment on GCE infra
• /werft with-integration-tests=all
  Valid options are all, workspace, webapp, ide, jetbrains, vscode, ssh

[werft-gitpod-dev-com]

started the job as gitpod-build-bmh-checkbox-input-component.1 because the annotations in the pull request description changed
(with .werft/ from main)

[selfcontained]

/werft run with-preview=true

👍 started the job as gitpod-build-bmh-checkbox-input-component.3
(with .werft/ from main)

[selfcontained]

Slightly increasing size of input labels, and making them bold.

[easyCZ]

LGTM

/hold in case you want feedback from design

[selfcontained]

/unhold