[resource loader] don't swallow errors thrown in resource reload event listeners

[rhysdh540]

this caused me some pain while debugging

[SpaceWalkerRS]

I would prefer (and intended) for exceptions to be re-thrown rather than just logged. I'm 99% certain exceptions thrown during the RESOURCE_RELOAD_START event are already re-thrown as that's handled in SimpleResourceReload, and it's just the RESOURCE_RELOAD_END event that's the issue.

I reckon the best course of action is to pass a finalTask to the resource reload in addition to the initialTask. That way it can easily be extended and the resource reload will take care of making sure it's run at the end and on the reload thread (which ig right now is not a certainty).

Let me know if you're up for that, otherwise I'll have a go at it.