Logging: Add WU# to associated HTTP transfer messages

[Hou5e]

Feature Request: For the log messages, adding the WU# to associated HTTP transfer messages would be very helpful for viewing and filtering the messages for debugging.

Example (4 out of 5 messages below are for WU17, but are not labeled for WU17):
00:52:42:I1::Added new work unit: cpus:1 gpus:gpu:02:00:00
00:52:42:I1::WU17:Requesting WU assignment
00:52:42:I1:OUT35:> POST https://assign6.foldingathome.org/api/assign HTTP/1.1
00:52:42:I3:Connecting to assign6.foldingathome.org:443
00:52:43:I1:OUT35:< assign6.foldingathome.org:443 HTTP/1.1 200 HTTP_OK