Invalidation of the Metadata cache after Transaction modification

[xgreenx]

The Metadata shouldn't affect the correctness of the code. We use it during serialization/deserialization and caching of the transaction id. If someone modifies the transaction after caching, the cache and transaction may be invalid or create incorrect behaviors.

Maybe we need to invalidate the cache if someone modifies the transaction(or if someone modifies only valuable parts). Or wrap the transaction into a Cached type as we did with Checked.

Note: The Interpreter also modifies the transaction outputs, but they shouldn't invalidate the cache.

Ref FuelLabs/sway@4c9ad3e