Use a timer-based search activation algorithm to prevent Nautilus spamming its search engines (improve live filtering search-as-you-type performance)

Similar to what I'm recommending in gedit at gedit#398 and elsewhere...

Unless I am mistaken (based on my observations of the floating statusbar, and some very light peeking at Nautilus' files in gitlab), it seems that everytime I type a character, Nautilus immediately triggers a search query (to tracker or whatever search engine is available to it) without any delay to see if I will type more characters... and that's terrible for performance. It does too much work, at the wrong time (see @federico's timeless performance optimization presentations/principles).

I suspect Nautilus could get much better performance by using a timer-based search approach with just a tiny amount of delay, with logarithmic back off (ex: the first 2-3 characters have a longer timer than the 10th or 15th, for example), to avoid spamming your search engines. This is what I did in Pitivi years ago and it made a huge impact on performance, and I will ensure this sort of optimization is done in GTG as well. See https://github.com/getting-things-gnome/gtg/issues/281 as I go into a more detail over there regarding the ideas of how this can work. It has now been implemented in GTG, and I've seen it make a huge difference in performance over there too.

Please consider this potential performance optimization for Nautilus as well :)