Add/migrate to Safe Decoder Service

[iamacook]

Description

The Safe Decoder Service effectively replaces the data decoder of the Transaction Service. It improves upon the existing implementation, particularly by following proxy contracts. We should migrate to the service due to this.

The return type of the new service differs to the existing one and it is used extensively across mappers. We should (initially) consider remapping the response for direct usage and push to deprecate it, across all entities that use it as well.

Requirements

• Add Safe Decoder datasource and entities.
• Add compatibility layer between existing data structure and new one.
• Address migration to new structure (likely in follow up issues)

Additional information

No response

[iamacook]

I have already stashed a local implementation of the relative datasource/domain layers from initial experimentation.