Observation request ignored when resource is first dynamically created

[farlepet]

If a GET request to a dynamic resource requests to be an observer, it will be ignored if this is the first time the specific resource has received a request. Subsequent requests behave as expected.

[farlepet]

Seems to be a limitation of how libcoap operates, due to how we are using the unknown resource for dynamic resources. Does not appear to be any real way to work around the issue without using a different CoAP library, or creating one from scratch.