[Telemetry] - Implement python-can in tpu_telemetry to fetch and handle CAN errors.

[jr1221]

Description

Right now CAN error frames are ignored by Calypso. Knowing these occur and what they are may help debugging, especially if the bus sruvives in listen-only mode.

Acceptance Criteria

• Uses just the library socketcan
• Listens for can errors and sends them over mqtt (w/o protobuf)
• Limits amount of errors collected to 10 at one time

Proposed Solution

Spec.
Add a can_errors.py in poll_data which is stateful class instantiated by main.py (i.e. listens for can messages constantly). It will form a listener using the environment variables inherited (probabaly created here). Upon recieving an error frame (see first link on how to check that), the program will store that error frame in a sort of que. This que should be limited in length to a reasonable amount (i.e. 10 frames).

Main.py will query fetch_data_no_compress as part of its normal loop and it will return [(topic, payload)] where payload is the error frame which will then be published as is, and topic is listed in the first link. Make sure to skip protobuf compression, this will not be like the other poll_data files and that is OK.

[jr1221]

Edit: See confluence https://nerdocs.atlassian.net/wiki/spaces/NER/pages/235438149/MQTT+messages+not+from+Calypso#CanError
We will be using protobuf.

[jr1221]

In progress added (but not working) in #150 . Please branch from that if you want/have time to continue.