Weird behaviour when creating subscriptions

[whitep4nth3r]

Today I attempted to create a push subscription without an endpoint. I wasn't provided any error feedback, but the UI did not allow me to create that subscription.

When a user tries to create a push subscription, error states should be shown if not all required information has been filled out.

Additionally, required fields should be indicated in the UI.

Conversely, I was just able to create a push subscription without an endpoint — and this is the subscription I am now not able to delete as referenced in https://github.com/orgs/sailhouse/discussions/16.

It's unclear whether an endpoint is required or not required – but I'm guessing it should be required, given a push subscription needs something to push to!

[estephinson]

Have tidied up the form validation around here, hopefully sorted things out a bit but will do some digging to double check.