Add a virusscanner to the ocis_wopi example

[mmattel]

Referencing:
owncloud/docs-ocis#775 (Evaluate Easy Entry Docs)
owncloud/docs-ocis#774 (Howto: ocis on Ubuntu with docker compose)

As preparation for the upcoming doc tasks (see above), I saw that an anti virus scanner is missing in the ocis_wopi example.

Post a short discussion with @fschade, he suggested to create a ticket to fix this.

Note that if adding this, we can also "tune" or improve - if necessary - the example provided.

What we have to do is, to update the readme and also link the admin docs.
(Note for the readme: #8846 (Allow to run wopi example deployment with podman) )

@micbar @fschade @tbsbdr

[mmattel]

@tbsbdr this one could be used as a configurable overlay #9229 (enhancement: add clamav docker compose example)

[tbsbdr]

As of now I don't want ClamAV in the easy entry docs, primarily because there is no easy way to remove false-positives from quarantine.