Show XLoad per load source, Predheat hysteresis off, service API

What's Changed

Improvements

• Re-work execute code to account for calling service last by @springfall2008 in #1826

The service API is called after all register changes to help with some inverters that use them.

• Adding Predheat hysteresis_off by @springfall2008 in #1827

Added a hysteresis off setting for Predheat.

• Split out load data in plan debug, add predheat off hysteresis by @springfall2008 in #1830

In plan_debug mode you can now see each load source.

Bug fixes

• Clip off slots regardless of min_soc setting by @springfall2008 in #1828

Setting min_soc left around useless charge slots, now they are clipped.

• Gate changes to settings in monitor mode by @springfall2008 in #1829

Monitor mode would reset reserve/charge/discharge rates - this is now fixed.

Full Changelog: v8.8.20...v8.9.0