Add links to execute notebook workflows on configured platforms

[Schpidi]

For workflows provided as Jupyter notebooks the OSC should show links to use the notebooks on configured platforms like EDC or DeepESDL.

The proposed approach is to use nbgitpuller links where the required information is retrieved as follows:

• JupyterHub URL - from OSC deployment configuration - nbgitpuller must be installed
• Git repository URL and branch - from link element in OSC entry with "rel": "git"
• File to open, path to notebook in Git repository - from link element in OSC entry with "rel": "notebook"
• Application to Open - from OSC deployment configuration, default JupyterLab

[Schpidi]

Maybe it would be an idea as step 0 to also store the URL of the publishing platform in OSC and first add a link to execute on the same platform. Step 1 would then be to extend with links for EarthCODE integrated platforms.

[Schpidi]

Step 0 is supported in the initial proposal visible at https://osc-staging.earthcode.eox.at/workflows/esa-cci-permafrost/record