`VeryGenericIndicator`s no longer support ID-instancing

[ES-Alexander]

Bug description

#1778 transitioned Very-Generic-Indicator widgets over to using the data-lake, but in doing so removed the ID-separation/instancing functionality.

Steps to reproduce

1. Configure a VGI
2. DISTANCE_SENSOR/current_distance is available, instead of DISTANCE_SENSOR/id=0/current_distance 🙁

Primary pain point(s)

It's no longer possible to differentiate between messages from independent distance sensors, batteries, GPS units, etc.

Additional context

This may have broken several people's VGIs, and is functionality the data-lake should have anyway (MAVLink message fields aren't useful if they can flip-flop between values from different hardware instances).

Discovered while documenting.

Prerequisites

• [x] I have checked to make sure that a similar request has not already been filed or fixed.