Signature v field serialization

[i-skrypnyk]

Description

Signature v field json representation was wrong - the value should be 0 or 1

Jira Ticket

https://horizenlabs.atlassian.net/browse/SDK-1627

Changes

Added a new JsonSerializer specifically for signature.v field - it checks the type of the transaction it is part of, and if the type is legacy - v field is 27 or 28. If the type if EIP1559 - v field is 0 or 1

Checks

• [x] Project Builds
• [x] Project passes tests and checks
• [x] Updated documentation accordingly
• [x] Breaking changes have been correctly tagged and notified

Additional information

[paolocappelletti]

please update changelog.md also