Draft: New schema parser

[Kriskras99]

This PR is not ready for review, see it more as a progress update.

The new parser uses a different JSON library sonic which allows the parser to iterate over borrowed strings from the file. This saves a ton of heap allocations. sonic also has SIMD optimisations when RUSTFLAGS="-C target-cpu=native" is used, but on the small files we generally have, the impact of that is small.

TODO:

• Proper error handling instead of panicking everywhere
  • Including schema path as is done in fix: Prevent users from setting a non-zero precision #670
  • Dedicated parse error that doesn't require the whole Error::new(Details::...)) until we're at the edge
• Recursion and allocation limits
• Test against all the parser tests

Parser	Small record	Large record
Old	23.5 us	25.7 ms
New	15.8 us	16.0 ms
Old (native)	24.0 us	26.1 ms
New (native)	13.8 us	15.6 ms

1. The large record is large_schema.asvc
2. The small record is RecordWithRequiredFields.avsc
3. Take the benchmarks with a grain of salt, laptops are quite bad for benchmarking.