tryCatchLog for each main observer method. When error shows:
a) we display browser alert
b) we print the current state (erroneous one) to the console (or events logger db)
Some exceptions (also extra but higher priority):
a) when error shown during executing restore method we:
before starting restore we save the previous state (if the state was empty it's okay)
Extra:
a) We save state before each operation changing cohort state (steps, filters) as a queue of states
b) When the error is shown we display modal that allows to restore previous state (selected one from history?)
restore
method we: