must-gather: add version file for programmatic analysis #3470

Describe the bug
The cluster logging must-gather does not produce a /must-gather/version file. According to the must-gather enhancement (please see the point 3), must-gather images should produce a text file at /must-gather/version that indicates the product (first line) and the version (second line, major.minor.micro-qualifier), so that programmatic analysis can be developed.

Environment

• OpenShift Cluster Logging versions that include must-gather golang code.

Logs

Expected behavior
Running oc adm must-gather oc adm must-gather --image=quay.io/openshift-logging/cluster-logging-operator:latest -- /usr/bin/gather should produce a version file in the must-gather output with the following format:

Red Hat OpenShift Logging/must-gather
6.7.0

Actual behavior
No version file is produced in the must-gather output.

To Reproduce
Steps to reproduce the behavior:

1. Run oc adm must-gather --image=quay.io/openshift-logging/cluster-logging-operator:latest -- /usr/bin/gather against a test cluster
2. Inspect the collected output directory
3. Observe that no version file exists

Additional context