Add caching of downloaded actions to achieve parity with the tool cache functionality

[Benjamint22]

This added functionality makes the use of real time NFS tool and actions caching possible.

Actual Changes

• add environment variable ACTIONS_RUNNER_ACTION_ARCHIVE_EXTERNAL_CACHING_ENABLED which maintains current actions caching functionality (downloads actions without caching) while allowing for external caching functionality
• extended the functionality of actions downloads to copy to cache location if not found in cache location if the above environment variable is true
• added workflow output to indicate that the copy took place

Authored by

• Tucker Fowler (The Home Depot, [email protected])
• Benjamin Taillon (The Home Depot, [email protected])