Implement Payload / Blob type conversion in rust, and replace golang implementation

[litt3]

• We need to have an implementation of the conversion pipeline bytes -> blob -> payload in rust, to be used for use with fault proofs
• It seems like a large risk to try to maintain two implementations in perfect lockstep
• Therefore, we should reimplement this data pipeline in rust, and make that the sole source of truth. Golang code that needs to operate on payloads and blobs can leverage the rust library
• there will still need to exist golang structs for Payload and Blob, but all conversions and the checks that go along with them will be delegated to the rust library