Add min/max physical current limit to loadpoint

[naltatis]

reopened the reverted https://github.com/evcc-io/evcc/issues/21179

fixes https://github.com/evcc-io/evcc/issues/21179 fixes https://github.com/evcc-io/evcc/issues/13355 fixes https://github.com/evcc-io/evcc/issues/21885

⚡️ introduce add min/max physical current 🖍️ define range in loadpoint via config ui (no new ui, repurpose existing min/maxcurrent inputs) 🖱️ ensure that ui options and api values stay in the defined boundaries 🪄 auto-adjust min/maxcurrent when physical current range is changed to avoid broken config

todos

• [x] decide backport to evcc.yaml (minphysicalcurrent: 6)
• [x] add/adjust e2e tests

config ui

loadpoint settings (main ui)