Rename "depends" keyword in default content to "dependencies"

Replaced the "depends" keyword with "dependencies" in default content and removed the old "depends" keyword.

The PR needs to do three things:
1. Change the internal API to accept "dependencies" alongside "depends".
2. Update tests to check for "dependencies", leaving some sample code to use the legacy "depends" keyword.
3. Add a legacy test that supports the "depends" keyword.
4. Mark usage of "depends" as deprecated.

The PR only updates the sample code that's part of the tests, more work is needed.

My apologies for all the commits, I had to read some docs for proper implementation. I took a swing at this, not 100% that my approach is correct here. Needs a review.

Okay, I think I've gone as far as I can on this one. Someone else will need to take a look and work this one out.