Cache static indicator control configuration to disk

[rmartz]

In azavea/temperate#998, we wanted to save the roughly-static configuration (Scenarios, models, and dataset) to disk, to alleviate the user having to load this data during every visit. Because the caching is done within the respective services, this was expected to be overly challenging to do within Temperate, and would require updating the Climate Change Components directly.

For these services, we should attempt to use a more persistent caching service if possible. However, we may need to investigate if it would be possible to invalidate the cache, should we introduce a new dataset or change the models we support, for example.