Change of default docker image name in CM

[arjunsuresh]

We needed to change the default container image name to also include the variation tags as variations of a given script might require a different docker container - for example Nvidia and Intel implementations are different variations and sometimes each benchmark of a vendor like Intel might also need different docker container. Currently we are adding the user specified tags as the image name with "," and "_" being replaced by "-" as follows. But this is not a consistent naming methodology and we probably need to come up with a better one.

local/cm-script-app-mlperf-inference-generic--nvidia--sdxl--tensorrt--cuda--test--r4.1-dev-default--offline:ubuntu-20.04-latest