Add samples for batching, large file upload and page iterator to reference docs

[Ndiritu]

Update:

• [ ] https://learn.microsoft.com/en-us/graph/sdks/paging?view=graph-rest-1.0&tabs=csharp
• [ ] https://learn.microsoft.com/en-us/graph/sdks/batch-requests?view=graph-rest-1.0&tabs=csharp
• [ ] https://learn.microsoft.com/en-us/graph/sdks/batch-requests?view=graph-rest-1.0&tabs=csharp

[msollanych-tt]

Please do this, it's not clear what the preferred way is to iterate through a collection presently.

[sanmai-NL]

As for batching, it's unclear to me how to batch get()s.