Offer more option for displayed kernel name

[fcollonval]

Problem

The naming options available does not allow to distinguish some kernels. In particular if you install ipykernel and xpython in the same conda environment, they will have identical Language and Environment name.

Proposed solution

This PR extends the field names available for name_format while ensuring backward compatibility and maintaining the default name.

name_format: String name format
Default: '{language} [conda env:{environment}]'
Available field names within the string:

• {0} = Language
• {1} = Environment name
• {conda_kernel} = Dynamically built kernel name for conda environment
• {display_name} = Kernel displayed name (as defined in the kernel spec)
• {environment} = Environment name (identical to {1})
• {kernel} = Original kernel name (name of the folder containing the kernel spec)
• {language} = Language (identical to {0})

[fcollonval]

@mcg1969 would you have time to review this?

Do you have time or can I help you cut a new release afterwards to publish #182 and #184?

[mcg1969]

Thanks for pinging me directly, @fcollonval — I do see those notifications much more readily.

[mcg1969]

It looks like our master build CI is failing because of this:

https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/