Support pagination for Xray events for the tasks table

When integrating Xray with Artifactory and upon trying to index repositories Xray will send an index request for indexing number repositories.
Different repositories may be huge and contain millions of artifacts.
This can cause a high number of events in the tasks table.
In addition, re-indexing requesting on Xray may also fill again the tasks table with events (which some might be duplicated).
We saw that in case this number is too high, Artifactory will have difficulties to load those events which will cause Artifactory to stop sending events to Xray.
This will cause the indexing process to be stuck.

Pagination will be a good solution to the above problem.