translations_taskgraph.util.dict_helpers.deep_get doesn't support lists

[gregtatum]

I have some configs that use lists in the yaml files, that I'd like to build kinds from. Currently deep_get doesn't support lists. I would expect the [0] syntax to work, or alternately a .0 would work, but the function uses a dict .get method, which isn't support by lists.

tasks:
    teacher-{src_locale}-{trg_locale}-1:
        task-context:
            from-parameters:
                url_prefix: training_config.continuation.models.teacher.urls[0]
    teacher-{src_locale}-{trg_locale}-2:
        task-context:
            from-parameters:
                url_prefix: training_config.continuation.models.teacher.urls[1]

[ahal]

Indeed, this would be a handy!

This is similar in spirit to:
#608