Cleanup

[#74311876]

* Remove unecessary Noaa interface
* Change TailingLogs and RecentLogs to return LogMessages instead of Envelopes
* Split out DebugPrinter type and SortRecent function into own files/tests

Signed-off-by: Joseph Rodriguez <jrodriguez@pivotal.io>
Update events library to include Error events

[#74311876]
Return termination errors

* TailingLogs returns errors on separate error channel
* Stream/Firehose submit errors on same channel as other events
* Where possible, we use constants for the error type so that they are easy to detect programmatically.

[#74311876]

Signed-off-by: John Tuley <jtuley@pivotal.io>