[TECH-DEBT] Refactor Meta Transactions for Consistency and Efficiency

Optimise Meta Transaction handling to reduce redundant deserialization and improve code consistency.

**Background & Problem Statement**

- Currently, the v1 transaction instances are only partially deserialised. However, many operations require access to fields in the unserialized portion if available. The current approach constructs a Meta Transaction by fully deserializing a reference to a transaction, which results in:
- Duplication of the original transaction data.
- Calling code inconsistently using both the original transaction and the Meta Transaction interchangeably.
- Suboptimal logic leading to inefficiencies and tech debt.

**Proposed Solution**

- Modify the Meta Transaction to hold the instance of V1 transaction as an inner field instead of duplicating it.
- Access fields from the inner transaction via getters instead of maintaining separate copies.
- Implement lazy deserialisation for fields that are needed dynamically rather than deserialising everything upfront.
- Enforce that all business logic interacts solely with the Meta Transaction, avoiding direct manipulation of the partially deserialized v1 transaction instance.