remove `isLegacyGetEnabled` flag from `Data` and `Cache` service

[TillaTheHun0]

Related to #531 and #550. At some point after #550, we will need to remove this flag entirely, dropping support for the legacy shape.

This should be a major release of hyper core

As a hyper developer
I would like hyper data service and hyper cache service "get" apis to return a hyper response shape
So that consumers will receive the hyper response shape across all hyper service apis

Scenarios

Only allow hyper response shape

GIVEN I am a developer
WHEN I am calling the Data Service "get document" or Cache Service "get value" api
THEN I will receive the hyper response shape