use management json-ld context in samples

# Feature Request

We should use `https://w3id.org/edc/connector/management/v0.0.1` json ld context in samples

## Which Areas Would Be Affected?

_e.g., DPF, CI, build, transfer, etc._

## Why Is the Feature Desired?

_Are there any requirements?_

## Who will sponsor this feature?

_Please @-mention the committer that will sponsor your feature_.

## Solution Proposal

_If possible, provide a (brief!) solution proposal._