Container serialize/deserialize: Do we need the keys?

[inducer]

When reviewing #91, it occurred to me that, at least for all our current use cases, we're completely fine with "positional" deserialization, and the keys are kind of a waste. Should we get rid of them?

One counterpoint is that the keys do provide metadata that pytato uses to generate better names.

cc @alexfikl @thomasgibson @kaushikcfd Thoughts?

[inducer]

(But the naming concern feels a bit orthogonal: That metadata could conceivably be added by/obtained from someplace else.)

[alexfikl]

Another counterpoint is that they're quite useful to check that deserialize_container didn't get garbage data.