[web] Introduce clearTooltip and renderTooltip functions in TooltipContext

Summary: Implementation of functions provided by tooltip context. The render function returns callback that should be called later by component calling to render tooltip (to correctly hide tooltip with delay).

Test Plan: Flow; The functions has been tested together with rest of diffs stack.

Reviewers: tomek, atul, abosh

Reviewed By: tomek, atul, abosh

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D4909