Add OrderedDict. Refactor Dict.render to utilize OrderedDict

[rainforest-bailey]

I would like to add a companion type to 'Dict', an 'OrderedDict', that will retain original ordering on keys.

[rainforest-bailey]

For additional context on why this feature is useful. When generating code to initialize a struct, it is beneficial to be able to control the order in which fields are defined. I found myself comparing my code gen to an existing spec definition. Ideally, I would be able to visually scan the 2 side by side, but I had to search each field individually, which was more cumbersome.