Fetch supported LED config from Bus

[netmindz]

Following on from this PR #4056

Replace convoluted logic in settings_leds.htm with config requirements supplied in the LEDType data

Motivation - #3777

[blazoncek]

@netmindz please take a look at 6f3267a
Implements similar as this PR but does not change Bus class. Instead it utilises BusManager and uses LED type convention to select appropriate GPIO text.

EDIT: There are other (mostly) irrelevant changes throughout bus_manager files to improve readability and optimise code.

[blazoncek]

Except for GPIO field names I think this PR has become obsolete.
Will you expand on GPIO or move that into HUB75 PR? I would prefer latter.

[netmindz]

I'll still like to remove things like IP address from the html, but certainly anything in here needs to be redone against the final bus-config