feat: adds ktlint gradle plugin

[jamesarich]

Adds ktlint gradle plugin to provide gradle tasks for ktlint style checks and autoformatting.

Also includes baseline files that ignore any existing issues to focus on ensuring cleanly styled code is added.

[jamesarich]

We could also consider adding github a status check for this.

[andrekir]

We could also consider adding github a status check for this.

yes, would be nice to run detekt and ktlint early in the CI