Refactor replication validation

[Neylix]

Description

Refactor PendingTransactionValidation to expose public function that are now called by ValidationContext.
Functions can now be simply unit tested

Avoid code duplication by using ValidationContext during replication validation in TransactionValidator

Also verify PendingTransactionValidation during replication validation

Refactor LedgerOperations to use a more friendly struct and reduce code duplication

Also split LedgerOperations calculation in a new module LedgerValidation and let only the ValidationStamp LedgerOperations for serialization

Fixes #907

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules