fix(angular-output-target): multiple targets do not overwrite each other

[sean-perkins]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally for affected output targets
• Tests (npm test) were run locally and passed
• Prettier (npm run prettier) was run locally and passed

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

When referencing multiple instances of the Angular output target in your Stencil project, it will only generate the last instance of the output target.

Due to invalid global state caching, the last executed validate step will be used for all generate steps of the output target. This is not desired and prevents using multiple instances of an output target.

Issue URL: N/A

What is the new behavior?

• Block-scope cache the validated output target across the validate and generator steps - does not cache across output target.
• Developers can use multiple instances of the same output target in their projects.

Does this introduce a breaking change?

• Yes
• No

Other information