There is no reason why Ctrl-A should be a NOP when you have an image
selected.

No test, there is one in the cp-6.0 copy&paste code, that coverage will
arrive as part of that copy&paste code forward-port.

Change-Id: If0013ee0e9ff9a6fb038a22de7b5d3c76e5c52b9
Reviewed-on: https://gerrit.libreoffice.org/73118Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins