Freeze dictionary keys to make them hashable (#228)

* Freeze dictionary keys to make them hashable

* Also freeze set elements (need to be hashable)

* Fix handling of indefinite lists vs definite lists

* Ignore linter error

* Add frozenlist to dependencies

* Do not recurse on hashable (and hence frozen) values

* flatten helper methods

* don't need to recurse into frozen set since it's hashable

* relax frozendict version for uplc

* need to add more primitive types or typegaurd errors

* simplify logic (containers are already handled)

* add frozen dict to default_encoder

* only freeze keys

* add indefinite frozen list to default_encoder

* Return indefinite list

* Freeze set members

* freeze result of to_primitive

* Format

* use latest frozendict

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Co-authored-by: Julius Frost <[email protected]>

Author: nielstron