Currently when checking for duplicate keys, we insert the value of the
key as is in a set then check for unicity against those. When the key is
an object, we check for duplicates based on object identity, whereas the
keys are used by owl as strings, and so using objects can cause
duplicate key errors that do not throw correctly but crash in the owl
internals.
This commit fixes that by making the duplicate checking code serialize
the key to string before insertion and when comparing against existing
keys.
This commit makes it so that when an error occurs in an owl app and none
of the registered error handlers are able to handle it, we rethrow the
error instead of just logging it to the console and swallowing it. This
allows users of owl to handle errors that happen in owl applications by
using event listeners for error and unhandledrejection events on the
window.
Samuel Degueldre