[Feature Request]: Add support for Google Secret Manager

[mattcasters]

What would you like to happen?

It would be nice to have a way to look up secrets in Google Cloud Platform Secret Manager.
In addition to the pull request for issue #3454 we can define another plugin to resolve variables for Secret Mangers

Expression #{name:secret-key} would need to resolve the key to the latest version of a secret with the given key.
The project ID and option location ID should be configurable in the metadata.

Issue Priority

Priority: 3

Issue Component

Component: Other