Add product quantity component

[lucasecdb]

What problem is this solving?

Adds the product quantity component that will be used in the new checkout. This PR also adds the showListPrice prop to the Price component, since we don't want to show it in the checkout listing.

Related clubhouse story

How should this be manually tested?

Workspace

Checklist/Reminders

• Updated README.md.
• Updated CHANGELOG.md.
• Linked this PR to a Clubhouse story (if applicable).

Screenshots or example usage

Type of changes

✔️	Type of Change
_	Bug fix
✔️	New feature
_	Breaking change
_	Technical improvements

[vtex-io-ci-cd]

Hi! I'm VTEX IO CI/CD Bot and I'll be helping you to publish your app! 🤖

Please select which version do you want to release:

• Patch

• Minor

• Major

And then you just need to merge your PR when you are ready! There is no need to create a release commit/tag.

• No thanks, I would rather do it manually 😞

[vtex-io-docs-bot]

Beep boop 🤖

I noticed you didn't make any changes at the docs/ folder

• There's nothing new to document 🤔
• I'll do it later 😞

In order to keep track, I'll create an issue if you decide now is not a good time

• I just updated 🎉🎉

[vtex-io-ci-cd]

Your PR has been merged! App is being published. 🚀
Version 0.17.0 → 0.18.0

After the publishing process has been completed (check #vtex-io-releases) and doing A/B tests with the new version, you can deploy your release by running:

vtex deploy [email protected]

After that your app will be updated on all accounts.

For more information on the deployment process check the docs. 📖