WIP: feat(Api): add v2 OCS Api to get table/view rows

[blizzz]

What is left is now basically tests. And removal of old internal method. And deprecation of v1 endpoint if any. Also TODOs in the code, there was some prototyping.

Intended test matrix:

test matrix.ods

[stefan-niedermann]

Feature requests from a client dev:

I'd like to take the chance an post some requirements I have as a client developer to enable a fast synchronization mechanism with a little data footprint.

1. Implement an If-Modified-Since header based on the lastModifiedAt property on each row to exclude "old", already known rows to reduce traffic. This covers newly created and edited rows on the server since the last synchronization
2. This raises the question about how a client can know that and which rows have been deleted on the server since the last synchronization. Ideas:

• Provide an ?properties[]=id query parameter, that only returns the ids that are currently on the server to save traffic and still know all available rows
• Just like the solution above but a separate endpoint, that directly returns a flat number array