Explicit semantic data types for ChargePower and DischargePower

[christianparpart]

What's needed?

Add two more boxed types

• ChargePower
• DischargePower

Both reflecting non-negative power with the semantic meaning encoded into the type system.

There shall be convenience methods like

• @staticmethod from_power(Power), and
• as_power(self) -> Power

Proposed solution

s.a.

Use cases

as discussed in the meeting, to encode meaning into the power values to catch value errors as early as possible, also aiding code review.

Alternatives and workarounds

No response

Additional context

in the FCR Prequalification Actor we've prototyped the use of such abstractions and had quite positive impressions about it.

[llucax]

I guess the battery pool charge/discharge command should return this new type, right? So this would be a breaking change?