CE-3164: Network error IOC log stream
Also includes a fix for CE-3333
To test: Kill internet to test browser error, send in bonkers time range to polling request in LokiPanel to get BE error.
Follow-ups:
- Spike a global warning when user looses internet connection, implying data can be stale CE-3334
- Status icon of IOC should indicate that it might not be correct, if there are errors fetching status. CE-3335
Browser error with previous successful requests
BE error with no previous successful requests
Browser error + no messages
Edited by Johanna Szepanski