Review name and description of `VoltageTransformer`

[llucax]

frequenz-api-common/proto/frequenz/api/common/v1alpha7/microgrid/electrical_components/electrical_components.proto

Lines 556 to 561 in 6e0a5b1

	// A representation of a voltage transformer.
	// Voltage transformers are used to step up or step down the voltage, keeping
	// the power somewhat constant by increasing or decreasing the current.
	// If voltage is stepped up, current is stepped down, and vice versa.
	// Note that voltage transformers have efficiency losses, so the output power
	// is always less than the input power.

This is more accurately described as a power transformer or simply a transformer.

A voltage transformer is a different thing used to lower voltage levels so that they can be measured: https://en.wikipedia.org/wiki/Voltage_transformer

I already mentioned the naming mismatch to @tiyash-basu-frequenz.

Originally posted by @shsms in frequenz-floss/frequenz-client-microgrid-python#165 (comment)