Add --silent option to disable console output

[larkoie]

Problem:
We are using Jfrog cli in Jenkins (through the Jenkins Jfrog plugin) and when executing a docker scan it really produces a lot of lines which makes our Jenkins log really unreadable.

A scan result file is always created (and you can specify the format with --format ) but there are no options to silent the console output of the JF client.
(On the Jenkins jfrog plugin this option does not exist as well)

New feature
You could add a --silent option to the cli so it would only output to scan result file and not to console.

Alternative solutions
I know that you can always play with your execution environment (ie: a shell) to tweak the output of a command, but in our case it can't work because we have to use the Jenkins Jfrog plugin (that is itself using the jf cli) and can't directly call it in a shell script.

Native support of a silent option is ideal.