Remove tooltips from symbol sidebar

Created by: umpox

Slack context: https://sourcegraph.slack.com/archives/C01LTKUHRL3/p1641303291183600

Expanding/closing our sidebar somehow takes ~1s and just hovering over the symbols in it is really laggy. Does one of you have a hunch as to what’s causing this? Profiler shows that it’s “Recalculate style” where it’s spending its time.

Removing the tooltips for now as they're causing performance problems when a large amount of symbols are present in the sidebar