Add QR code element

[bramkragten]

Proposed change

Adds qr-code element, can also be used in markdown.
This can be used by integrations for config flows for example.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[SirRufo]

Now the generated qrcode only contains the tag id. Is that for a special reason?

https://github.com/home-assistant/frontend/pull/19155/files/993800444fd0c7bffe7ab1d74d707f60deb2d96b#diff-9040cc559b745e39c903830a0a6b035286d19ffc87a62992c1ce69dd77284c33R122