⭐ Add output handler to store asset reports

[preslavgerchev]

Add a new --output-target flag that specifies a target where the scan report can be stored.
This currently only supports local files and AWS SQS urls. If no target is specified, it falls back to CLI reporting (which is the current default behaviour)

# for AWS sqs
~/go/bin/cnspec scan --output-target https://sqs.us-east-1.amazonaws.com/921877552404/myqueue --output json
# for local file
~/go/bin/cnspec scan --output-target file://somedir/file
~/go/bin/cnspec scan --output-target report.json --output json

for AWS SQS reporting only --output yaml and --output json are supported

[chris-rock]

Very nice structured implementation. I am just having trouble to get the local file reporter running.

[chris-rock]

Thank you @preslavgerchev