Fix: maxIncrease for solar inverter with PDL

[AndreasBoehm]

Fixes #1512

Description

Use inverter maxPower instead of configuredMaxPower for solar inverters with PDL to calculate the maxIncrease, because the limit will be distributed across MPPTs that can provide power by the inverter and not equally divided.

Example

HMS-1600
2 out of 4 MPPTs connected
max output set to 800 W
current output power 400 W

Old calculation

maxTotalIncrease: 800 W - 400 W = 400 W
max power per MPPT: 800 W / 4 = 200 W
current power per non shaded MPPT: 400 W / 2 = 200 W
max increase per non shaded MPPT: 200 W - 200 W = 0
max increase: 0 W * 2 = 0 W

missed out increase (if PDL or overscaling is available): 400 W

New calculation (inverter with PDL only)

maxTotalIncrease: 800 W - 400 W = 400 W
max power per MPPT: 1600 W / 4 = 400 W
current power per non shaded MPPT: 400 W / 2 = 200 W
max increase per non shaded MPPT: 400 W - 200 W = 200 W
max increase: 200 W * 2 = 400W

Example why we need to limit the maxIncrease to totalMaxIncrease

inverter with PDL only, 3 out 4 MPPTs connected, producing 600 W

maxTotalIncrease: 800 W - 600 W = 200 W
max power per MPPT: 1600 W / 4 = 400 W
current power per non shaded MPPT: 600 W / 3 = 200 W
max increase per non shaded MPPT: 400 W - 200 W = 200 W
max increase: 200 W * 3 =600 W

600 W + 400 W would exceed the max output of 800 W

[schlimmchen]

We'll discuss the conceptual change proposed in your comments later. The fix for #1512 seems reasonable.