Tools for creating an options map from the environment.

Internal API and base specs.

This doesn't live in unsiemly.core for two reasons:

* It's internal, and core is probably external-facing.
* Circular dependencies: anything can require this API ns, so it must not
depend on anything inside unsiemly.

Data transformation tools useful for SIEMs. Usually this is about format
conversion (e.g. seconds-since-epoch to ISO8601) or flattening data (e.g.
turning a map into a string).

Typically, you'll compose some of these functions and then use something like
specter or update/update-in to apply them to maps.