Add simple behavior monitoring to better address potential breakage issues

[jaceklyp]

Task/Issue URL: https://app.asana.com/0/0/1206706226010039/f

Description:
We want to identify behavioral signals that indicate a user is experiencing breakage.

Steps to test this PR:

1. Run UserBehaviorMonitorTests
2. Go through scenarios listed here: https://app.asana.com/0/0/1206706226010039/f and see if pixels are being sent.

[samsymons]

Looks great! Tested all pixels multiple times, checked the pixel names and that they're called in the correct places, and the edge cases pointed out in the previous PR are deemed acceptable by product, so we're good here once CI is green.

[samsymons]

New changes LGTM