Add support for Cisco IOL (and IOL-L2)

[kaelemc]

Cisco released IOL-XE publicly in CML. User @fluzzi did some amazing work and got IOL built into a container.

Containerlab PR - srl-labs/containerlab#2211

As per the discussion this PR adds IOL support and changes the following:

makefile.include

• Now deletes .bin files when 'cleaning' (IOL images are to be suffixed with .bin).
• New NOT_VM_IMAGE check added, if NOT_VM_IMAGE is declared and set to 1 in the image Makefile, the /common directory which contains the vrnetlab python files to support VM-based images, is NOT copied into the docker subdirectory of the image at build time. This doesn't affect existing images as if NOT_VM_IMAGE is not declared the copy will occur as expected.

IOL images are split into IOL and IOL-L2 directories which reflect the two image types. IOL-L2 has a slightly different initial config for the node as I couldn't get the management VRF working properly.

I got both images up and running fine with working dataplane.

The relevant containerlab PR will also be made to add the cisco_iol kind and interface aliases.

[hellt]

@kaelemc thank you
would you mind creating a cisco dir in the root of the repo and put those two there?
I plan to consolidate images, as we get a lot of them already, the flat structure doesn't make it easy anymore to browse the images