Better support of scrolling in Events Table while indexing is ongoing

The events table is filled with the number of events equal initial cache size (200) and the the user is able to look at the event after opening the table. In the background the trace is indexed so that it's possible to navigate in the table without having to load the whole trace loaded in memory. For that the back-end is indexing the trace and the front-end is periodically query the trace to get the number of events currently indexed until the indexing is finished. For each back-end query the `table-output-component` is updated with current total number of events.

The idea is that the user is able to scroll within the trace to the current number of events, event while index is ongoing. However, when scrolling to the end while indexing, then it seems that the view is refreshing periodically with back-end queries until indexing is finished. This is no ideal for large traces to have to wait till indexing is finished.


The implementation should handle scrolling while indexing so that users can start looking at trace events while indexing.

Start with the front-end `table-output-component` and the back-end indexing queries described in the issue. Reproduce scrolling to the end while indexing is ongoing, then trace the periodic updates that refresh the view. Done means users can continue scrolling and viewing newly indexed events without disruptive refreshes until indexing finishes.

Written by the indexing model from the issue text.