Added support for paging using cursor in search results.

[MiguelTVMS]

Now the SDK supports paging search results using the cursor query string parameter, as mentioned on this page in confluence documentation.

Here is a usage example:

var query = Where.And(Where.Space.Is("Default"), Where.Type.IsPage, Where.Title.Contains("Something"));
var hasNext = false;
var results = new List<Content>();
int limit = 25;
int start = 0;
string cursor = null;

do
{
    var paging = new PagingInformation() { Limit = limit, Start = start };
    var searchResult = await _confluenceClient.Content.SearchAsync(query, cursor: cursor, cancellationToken: cancellationToken);
    hasNext = searchResult.HasNext;
    cursor = searchResult.Cursor;
    results.AddRange(searchResult.Results);
    start += limit;
} while (hasNext);

[Lakritzator]

Looks like a very clean addition