[Feature Request]: harmonize square indexes (EDS vs ODS)

[odesenfans]

Implementation ideas

Some API endpoints provide square indexes relative to the EDS while others refer to the ODS. Most end-user use cases do not care about parity shares, therefore it would be nice to always use ODS indexes in user-facing endpoints.

Example:

• Blob.Get returns the blob index in the EDS.
• Share.GetRange takes an ODS index as input.
• Share.GetShare on the other hand takes an EDS index.