[web] Introduce TooltipContext

Summary:
Introduce context for rendering tooltip. It is similar to the one used with Menu component. It provides functions for rendering and clearing tooltip.
The funcitons will be implemented if next diffs.

Test Plan: The context is not used yet, tested after other diffs in stack.

Reviewers: tomek, atul, abosh

Reviewed By: tomek, atul, abosh

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D4908