support for creating google secrets from json file

[lpuskas]

Is your feature request related to a problem? Please describe.
Creating a google credential with the cli tool is cumbersome as lots of properties need to be manually copied over from the google credentials json file

Describe the solution you'd like to see
The cli tool can be enhanced to be able to generate the proper google secret given the credentials.json file content or the file location

banzai secret create -n google-secret -t google -f /path/to/credentials.json

Describe alternatives you've considered
Finding the credentials.json - considering conventional locations like./gke, or the local env
GOOGLE_APPLICATION_CREDENTIALS if nothing provided to the command (--magic flag maybe)