CIP-1421 add tango board DS

Added Tango board DS for monitoring telemetries and status registers on a talon board. The device gets telemetries such as voltages and temperatures from the InfluxDB installed on the talon board, and also through subscribing to selected attributes from HPS device servers such as sysid, talon status, and 100g ethernet (todo).

The device is turned on by Talon LRU after it turns on the PDU. A catch is that Talon Board device will be in ON state before the HPS devices and InfluxDB are ready. In the future the ON/OFF commands should be run asynchronously, probably after upgrading the ska-tango-base version because it introduced the support for running slow commands asynchronously.

I skipped making unit test for this device. Most of its job is querying the DB and reading attributes from HPS device proxies. It is a lot of work to mock these interfaces and doesn't test much.

Device was tested on dev2 minikube and Talon2 and 3, mostly by running the MCS On command and reading attributes using Jive.

Relevant info: Talon Telemetry and Status: https://confluence.skatelescope.org/pages/viewpage.action?spaceKey=SE&title=Mid+CBF+Talon+Telemetry+and+Status InfluxDB installation: https://confluence.skatelescope.org/pages/viewpage.action?spaceKey=SE&title=Influxdb+and+Telegraf