feat(currency-convert): support zero decimal option

[Najibmansour]

Feature: Support zero-decimal option

Summary

This pull request introduces initial support for a zero-decimal option in the pricing/amount logic.
The core implementation is complete, but testing and documentation are not yet finalized.
This PR is intentionally opened early to share the approach and gather feedback before completion.

What’s implemented

• Core logic to handle zero-decimal values

What’s not done yet

• Unit tests
• Integration and edge-case tests
• Documentation updates

Testing

• Tested failing on 3 locales working on issue
  (Tests will be added before merging)

###Documentation
Documentation will be updated once the behavior is validated and finalized

Work in Progress
Feedback is welcome before proceeding with tests and documentation.

[mastermunj]

Hi @Najibmansour , can you help share a few examples about the behaviour change? It will be clearer to understand.