Deprecate built-in Cordova adapters (#297)

Add a deprecation utility (`logDeprecation`) that emits each warning
at most once per page load, keyed by a unique code (KC-DEP-###).

Use it to deprecate the built-in 'cordova' and 'cordova-native'
adapters at runtime, and mark them as deprecated in the type
definitions and documentation ahead of removal in the next major.

Closes #271

Signed-off-by: Jon Koops <[email protected]>

Set version to 26.2.4

Set version to 26.2.3

Set version to 26.2.2

Set version to 26.2.1

Set version to 26.2.0