VMware: clean up VNC console handling

Commit 61bfac8881dd6a71a572a54b2ea1680248fc4bc4 introduced
the VMwareVCVMOps class. This class specifcally treats VC methods.
The patch set moves the treatment for get_vnc_console to this
class.

The log message for the VNC console now has the instance as a
parameter.

Please note that there are already test cases for this.

Change-Id: I2b943558d96328580f5c8744945e5f5f1790c06f
Merge "VMware: clean up VNC console handling"