Add support for Hooks

[Brianwithay21]

This release adds support for creating Hooks using the CFN CLI Java plugin

• Initialize a Hook project with cfn init --artifact-type HOOK --type-name <type-name>
• For example: cfn init --artifact-type HOOK --type-name My::Test::Example
• Using cfn init without parameters will now first ask if you want to create a resource, module, or a hook. If you choose to create a hook, you will be asked to choose a language plugin. After choosing a plugin, a hook project will be generated with boilerplate code which you can use as a starting point to make your changes.
• Use cfn validate to validate your hook before submitting
• Use cfn submit to register your hook, making it available for use by CloudFormation in your AWS account

Related PRs:

• Add support for Hooks cloudformation-cli#861

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.