I thought it would be nice to have a Predicate for the typed value so that the developer can work with predicates as values comfortably. Then I noticed that hashing a predicate required `Params` which would have been annoying for converting a `TypedValue::Predicate` to `RawValue` and this led to a small refactor over how `Params` work.
We already had some fields in the `Params` struct that determine compatibility between encoded data. They can be seen as determining a kind of ABI compatibility. In general it's better if those parameters don't change so that different circuit configurations can still verify proofs from each other. So I decided to force those parameters to be constant in the code base and not allow the user of our library to change them. Many field element serialization/deserialization functions in our code depended on those parameters, and since now they are constant many functions get rid of the `Params` argument, which simplifies the code. This includes the serialization of a `Predicate` which was required to calculate its hash.
* Multi-batch splitting
* Invoke split predicates by name, passing in full argument list
* Reorder batches to prevent failure of forward references where possible
* Rename APIs for clarity
* Simplify example
* Add more docs
* Review updates
* Remove duplicate code
* Comment topological sort algorithm
* Basic frontend AST and semantic validation
* Intro statement support
* Simplify validator lifetime
* Fix arity validation
* Lowering and splitting
* Remove legacy processor and use frontend AST by default
* Use builders instead of creating middleware types directly
* Typos/formatting
* Improve error messages when overflowing a batch due to splitting
* Add FromStr implementation for NativePredicate
* Remove 'raw' fields, and switch HashHex representation to byte vector rather than string
* Simpler wrapper types for batch and intro predicate hashes
* Parse secret and public keys to their respective data structures earlier
* More detail around string escape validity
* Simplify native predicate arity handling and move method to NativePredicate impl
* Store hashes using middleware::Hash, and simplify lowering by using pre-parsed values
* Simplify predicate building
* Formatting
* Better error messages/suggestions for cases where predicate splitting fails
* Formatting
* Clippy fix
* Return error if we get a too-large int
