Add MQTT Handling for Retrieving and Publishing Camera Name

[melissadjadoun]

This pull request addresses the feature request outlined in PlanktoScope/PlanktoScope#225 to retrieve and publish the camera name via MQTT.

Changes Made:

• Modified run method in mqtt.py:
• Set up MQTT to listen on the topic camera/info.
• Added logic to respond to the action { "action": "get" } on the topic camera/info.
• The response includes the camera name and is published to the topic status/camera/info.

[ethanjli]

Here's my initial review. The next step will be to test this with changes to the Node-RED dashboard.

[ethanjli]

It looks like you made some changes in the adafruithat version of the hardware controller and you made some other changes in the planktoscopehat version of the hardware controller. For this PR, please always keep the adafruithat/planktoscope/camera/mqtt.py file identical to the planktoscopehat/planktoscope/camera/mqtt.py file - for example, make all of your edits in the planktoscopehat/planktoscope/camera/mqtt.py file, and then before each commit/push to GitHub make sure you copy the planktoscopehat/planktoscope/camera/mqtt.py file to adafruit/planktoscope/camera/mqtt.py (overwriting the previous file at that path).