Configurable resources for a session

[diocas]

We discussed that we should provide a form for users to pick resources to be attacked to a session. This way they can pick wether they want GPU's, vGPUs, access to Spark, access to Daks, etc.

For now we should offer the possibility to pick between GPU and vGPU. Then we will need to offer the option for Dask (once we have it integrated).
Then this will become very important once we switch the LCG selection to a project, instead of a session, which will require a different way of picking the availability of the (v)GPUs.

In the end, maybe this issue should be called "new spawner/configurations menu", as we will rewrite it completely.