Deprecations & upcoming breaking changes - v11.0.0

[elenagarrone]

ℹ️ Small breaking changes are more easily consumed when shipped together in a major version bump.

💡 When identifying such a change, such as removing a CSS var, add a deprecation notice and where possible provide deprecation warnings in the console.

💬 Add a comment to this issue to log current deprecations and upcoming minor breaking changes.

🚀 The pull request should be merged into the next branch, where it can be part of the next pre-release. At an appropriate time, next can be merged into master creating a major release of Canopy (with some nice release notes).

♻️ When released, this issue can be closed down and another one spun up for the next batch.