* Update tooltip trigger logic in AddObsButton for logged in
Refines the tooltip display conditions for AddObsButton. Now shows the tooltip for logged-out users after their second observation, and for logged-in users with 50 or fewer observations upon landing on the My Observations screen. Adds comments for future handling of users with more than 50 observations.
* Refactor the state justFinishedSignup into the layout store slice
* Refactor trigger logic and add conditions for when the tooltip would overlap with pivot cards
* Move files
* Basic AddObsButton unit test
* Add mock for addListener
* Basic test for tooltip
* Add tests for two conditions that require a card dismissal
* Wrap setState in act in helper function
