QZ-946 make @quartz/styles a dependency

[sezgi]

As part of https://github.com/Quartz/qz-react/pull/6454, this PR moves the @quartz/styles package into the dependencies so that qz-react can run @quartz/interface without errors.

When we move @quartz/interface into the qz-react repo, we won't need to import @quartz/styles any more.

[linear]

QZ-946 Bring @quartz/styles repo into qz-react

Currently, it takes many unnecessary steps to maintain the https://github.com/Quartz/styles repo: update package version, create release tag, use the latest @quartz/styles commit hash in qz-react PR until the @quartz/styles PR is approved and the tag is published, etc. This PR brings the styles from the @quartz/styles repo into the qz-react repo to make these styles easier to maintain.

Also planning the same for the @quartz/interface repo.

Keeping the @quartz/styles repo itself around for now, so the iOS app can keep using it.