Instead we will rely here on the implicit struct provided by the file
itself. This means that when the service_manifest.zig import is
assigned, we don't end up with a construct like "manifest.sts.sts" to
get to the sts service. This simplifies greatly the way that
servicemodel.zig needs to behave.
One down side, however, is that the structure does not seem
accessible with the current zig language, making metaInfo unable
to access itself as it did before. Or maybe it can, I just can't find
it. So, this change also adds a new "service_metadata" public constant
with the same declarations being published at the file level, and
that is the new return from the metaInfo function. Our aws.zig
only really needs the action and that metadata, so we're ok with that
even if there is some duplication (we could codegen pointers over, and
maybe should to save a little bit of space).
This increases compilation time significantly as all 260+ services
need to be analyzed by zig during compilation. I plan to change
the model from a single "services" constant to a function
that will import only services that plan to be used. This
might be in addition to the single constant to allow
consumers to choose short compile times or all services
support
