feat(resolver): Add a resolver for the cdk-examples repo

[wulfmann]

Some work was done initially to support templates found in the cdk examples repo, but it proved to be more complex than originally thought.

Some known issues:

• templates are nested under [language]. We'd need to have the user select their language.
• even more than [language], other groupings exist like: python ecs. We would need to recursively map the directories and gather only templates with a cdk.json. This would also make the current downloadAndExtract implementation pretty complex.

[wulfmann]

A quick-fix could be synchronizing the cdk-examples repo with the templates repo, but I don't really like that solution.