Better reporting when endpoint fails

**Is your feature request related to a problem? Please describe.**

This is from a debugging conversation with @ravescovi. When an endpoint fails with a ZMQ error, the endpoint appears to start, a series of log messages announce connection steps which seem to indicate that the endpoint is starting including `funcx-endpoint list` which indicates that the endpoint started only for it to fail silently later. The delay to failure is a problem, and the fact that the `funcx-endpoint list` only says `disconnected` rather than `failed` is a problem.

**Describe the solution you'd like**

Ideally the endpoint fails right away, however this might be difficult since the failure happens in the endpoint interchange which is a daemonized process. The next best option would be to have `funcx-endpoint list` be more descriptive with what failed.

**Describe alternatives you've considered**

This failure message pops up in the `interchange.stderr` and isn't reported at the end of the the `EndpointInterchange.log`. Having this error go the `EndpointInterchange.log` would have been ideal, one option would be squash the `EndpointInterchange.log`, `interchange.stderr` and `interchange.stdout` all into one `interchange.log`. Having three places to check is pretty bad.

**Additional context**
Following the instructions in https://github.com/funcx-faas/funcX/issues/393 fixed the ZMQ issue.