Right now, dash-renderer updates the page tab whenever there is a request in flight.

For fast updating callbacks, e.g. dcc.Interval, this becomes pretty annoying: https://community.plot.ly/t/how-to-avoid-updating-html-browser-title-when-using-interval-event/15379

This is one of the few "hardcoded" features in Dash that we should make configurable:

1. We could make this a config option to turn on/ off or change the text
2. We could remove it from dash-renderer and attempt to roll it in to loading states. However, loading states are currently configurable only per-component, not across the entire app.

Seems like (1) would be the way to go right now. It could be something like

update_page_title_during_requests = true / false / 'Loading ...'