Change static data file property names

[genehack]

I like "maintainers" and "title" since those are the key names in the Auspice JSON schema. Why not change SARS-CoV2-Datasets.yaml instead?

Because it wouldn't be just changing SARS-CoV2-Datasets.yaml; the change here wasn't to synch the community datasets YAML with the Covid YAML, but to synch it with the property names used by the DatasetType of components/dataset-select/types.ts.

Changing the Covid data file would require matching changes across the entire <DatasetSelect> component (and probably in the /ncov and /sars-cov-2 page components). The scope of that change felt much larger than "make /community work under App Router".

If folks feel strongly about making this change in the other direction, I'll make a distinct issue for it, but I don't think it belongs in this PR.

Originally posted by @genehack in #1194 (comment)

[genehack]

I looked at doing this, and was reminded that the data structure in SARS-CoV-2-Datasets.yaml is actually a mix of two different types of data: geographic regions, and datasets. They're currently both stored in a datasets key at the top level of the YAML, pointing to an array, and distinguished in practical code usage by which second-level keys are present in each element of the array.

I think the right thing to do here is to split the geographical region elements out into a distinct data structure, generate types for that, update the code, etc., then also standardize the keys used in the datasets data structures in SARS-CoV-2-Datasets.yaml and community-datasets.yaml.

I didn't feel like I had time to do that work and get it reviewed before I left, so I'm just removing my name from the ticket assignment, and leaving this open, either for future work or for somebody else to decide the juice is not squeeze-worthy.