Add a Non-Commerical License Option: CC BY-NC-SA 4.0

[NEStock]

https://creativecommons.org/licenses/by-nc-sa/4.0/, CC BY-NC-SA 4.0

EMBER will need the following license option to support BBQS project teams

cc @sandyhider @laurendiaz

TODO

• add enum value here: https://github.com/dandi/dandi-schema/blob/master/dandischema/models.py#L133

[yarikoptic]

@candleindark lets make that enum be built dynamically based on Config.licenses (of #294) -- which would be a comma separated list of licenses, defaulting to spdx:CC0-1.0,spdx:CC-BY-4.0. While constructing the Enum we would then verify that

• all licenses have spdx: prefix (we do make it explicit so later we might extend with support of some other prefix there)
• the spdx licenses provided are legit spdx licenses, as known now (so we do keep hardcoded list of known licenses). This would allow for any instance to extend with any spdx-valid license right away without changing dandi-schema at all

[candleindark]

@yarikoptic I want two adjustments regarding the implementation of Config.licenses.

1. I want Config.licenses to be of the type of list[str], which seems more intuitive and more ready for use.
2. If Config.licenses is to be made of type of list[str], I want to support the population of its value by treating the corresponding environment variable as a JSON-encoded string instead of expecting the environment variable to be a string of comma-separated list of licenses since pydantic-settings, by default, populates of fields of complex types like list, set, dict, and sub-models by treating the corresponding environment variables' values as JSON-encoded strings. I don't want to deviate from the expected format of a JSON-encoded string just for Config.licenses field since we may add some other fields with complex types to Config model in the future that expect JSON-encoded strings in the corresponding environment vars. (With that said, the comma-separate format is cleaner and can be implemented with a customer validator. I don't want it just because I prefer consistency and don't want additional documentation just for this particular filed.) If this adjustment is adopted the Config.licenses field can be set by the setting the DANDI_LICENSES env var as

export DANDI_LICENSES='["spdx:CC0-1.0", "spdx:CC-BY-4.0"]'

[yarikoptic]

ok!

[candleindark]

FWIW, SPDX licenses are the ones listed on https://spdx.org/licenses/, and we will use the machine readable version of the list https://github.com/spdx/license-list-data/blob/main/json/licenses.json.