* ntp: try using sntp app from lwip, drop ntpclientlib

* fix display

* thermostat: fix day and month getters

* test build sizes with scheduler

* use system timers for once-a-minute scheduling, no polling

* tick

* avoid timestamps, use tm

* drop utc rpn operator, add utc_hour and utc_dow

* try to build with old implementation too

* dep

* notify ws

* progmem

* cleanup types

* offset tm values by 1 to match existing schedules

* avoid using ntpclientlib with rpn

* test. show debug strings in sch

* fix secureclient

* consts, fix unsyncing when changing tz (and not triggering sntp after reinit for some reason)

* startup time in seconds

* same delay as lwip

* header

* assume build timestamp is unixtime

* cache server value

* fmt

* typo

* handle dhcp request

* rename

* web

* TZ.h

* add notice about what alias means

* fix disabling NTP_SUPPORT

* scheduled ticker

* same behaviour as old module

* rollback rpn dependency check, utc_ prefixes

* ...

* comments, refactor naming

- wrapper NTPClient class to avoid inadvertently calling NTP::getTime() while
setting things up
- only call NTP::getTime() when in loop(), install async TimeLib
sync provider and manually set TimeLib time
- randomize sync and delay times