<!-- Describe your changes in detail -->
This PR adds amount conversion framework to Opayo.
Opayo accepts amount in MinorUnit
To implement this **search_filter** feature, you'll need to modify these architectural layers:


**1. External Connector Integration**
   - `crates/router/src/connector/opayo.rs`
   - `crates/router/src/connector/opayo/transformers.rs`
   - `crates/router/tests/connectors/opayo.rs`

**Code Patterns Applied:**
- Define new data structures (2 changes)
- Implement new functions (4 changes)
- Extend existing types with new fields (9 changes)

**Detailed Identifier Changes:**


Commit 91146de2:
Files to modify:


**crates/router/src/connector/opayo.rs**
  Modify existing code

**crates/router/src/connector/opayo/transformers.rs**
  Modify existing code

**crates/router/tests/connectors/opayo.rs**
  Modify existing code
{"pr_number": 6342, "pr_title": "refactor(connector): add amount conversion framework to opayo", "merged_at": "2024-10-18T13:46:21Z", "intent": {"feature_type": "search_filter", "action": "add_feature", "entities": []}, "hierarchy": {"connectors": ["crates/router/src/connector/opayo.rs", "crates/router/src/connector/opayo/transformers.rs", "crates/router/tests/connectors/opayo.rs"]}, "change_types": {"structs_added": 2, "functions_added": 4, "fields_added": 9, "imports_added": 2}, "has_identifier_data": true, "commits_matched": 1, "match_method": "pr_number"}