Remove support for generating dotkit files (#11986)

Dotkit is being used only at a few sites and has been deprecated on new
machines. This commit removes all the code that provide support for the
generation of dotkit module files.

A new validator named "deprecatedProperties" has been added to the
jsonschema validators. It permits to prompt a warning message or exit
with an error if a property that has been marked as deprecated is
encountered.

* Removed references to dotkit in the docs
* Removed references to dotkit in setup-env-test.sh
* Added a unit test for the 'deprecatedProperties' schema validator