Add confetti after new onboarding flow

[selfcontained]

Description

• Updates the Company Website input to accept any string that validates as a url and not use an <input type="url"/>, as it's more restrictive then we'd like. Also updated the placeholder to example.com

• Adds a ConfettiContextProvider to drop confetti on demand from any component. The end of the new onboarding flow drops confetti now with this change.

const { showConfetti } = useConfetti();

// walla, drop confetti
showConfetti();

Confetti will automatically hide after it's all been dropped. You can also manually hide it, or inspect the current status of it's it being shown via additional props returned from the useConfetti() hook.

const { isConfettiShowing, showConfetti, hideConfetti } = useConfetti();

• 2 new dependencies were added for this PR as well.
  • validator (we're using this on the www website already) to validate a url string
  • react-confetti For confetti dropping. I've set it up to bundle split and lazy load so it's not including in the main bundle.

How to test

• Ensure your email is added to the newSignupFlow feature flag.
• Preview Env: https://bmh-onboar77a0b587f5.preview.gitpod-dev.com/workspaces
• Complete the onboarding flow in the preview environment.
• Company Website should accept a value like gitpod.io and not need a full url with a protocol.
• You should see confetti drop at the end of it.
• You can repeat the onboarding flow by visiting https://bmh-onboar77a0b587f5.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-onboarding-confetti.1 because the annotations in the pull request description changed
(with .werft/ from main)

[geropl]

Tested, and works! ✔️