Garanti circuits refactor

[0xSachinK]

Adds the suggested changes in #281

• [x] Refactored DividedHasher to BodySuffixHasher
  • [x] Remove body hash assert
  • [x] Use zk-email utils to pack bytes
• [x] Move BodySuffixHasher instantiation to circuits/garanti
• [x] Fix generate inputs ts
• [x] Use zk-email utils to pack bytes in send and registration circuits
• [x] Use zk-email EmailVerifeir in send and registration circuits. Just skip body hash check
  • [x] Extract out body hash using BodyHashV2 regex in individual circuits
• [x] Update max header bytes to 512
  • [ ] Todo: Does this work for outlook / hotmail emails? Nope, generate input fails
• [x] Update Body Hash regex v2 and tests [Confirm with Richard first]
• [x] Update subject regex; Remove requiring \r\n at the begging
• [x] Minor nits

[0xSachinK]

Body hash regex lgtm. Assuming that the simple canonicalization always has the \r\n followed by at least one space or tab.