[ESP401]evolution to handle batch of settings at once

[luc-github]

[ESP401] save one setting at once
Pro: it is atomic and has a small foot print - perfect for ESP8266
Cons: wear the flash slowly, need to repeat for each settings use bandwith if lot of seetings
Mitigation: we do not save settings on flash so often, so it is not big issue.

new [ESP401] save all settings at once
pro: it can be atomic or batch, it save bandwith and limit flash wearing
cons: cannot be applied to esp8266 due to memory limitation,
Mitigation: because of existing version, new version is not mandatory but considered as enhancement or nice to have

So I am currently considering such solution that would first be used on ESP3DLib and GRBL_ESP32 solution, then in ESP3D when ESP8266 is dropped, the webUI 3.0 could handle it as code is splited between targets

But it is not in top TODO list - so if anyone is willing to do a POC - or even full solution - please feel free