usually a good idea for clients like PuTTY, since these are sent by default
in the very first packet even before user types anything else
also restore iac+eof handling, which call close() on the stream

resolve #2563
resolve #2606

revert to pre b23137f cstrings
fix #2605

remove yet another deprecated gulp plugin, just calling it w/ through2

allow just "UTC", "Monday", "05-01", etc.
clarify webui paragraph and mention KEYWORD as an element

ignore sunrise and sunset keywords when sun module is disabled

move all of parsing to time module, test whether combined match works

github actions just happen to be in pacific time / utc-7 today

amends d9a7743d04

certain actions need to happen when
- starting restore()
- switching date within restore()
- stopping restore()

pretty good fit for an object and raii. so, using context struct to handle
sun{rise,set} initialization and per-schedule time match updates

sun{rise,set} event happens on a specific date, make sure it is also checked
fix double action trigger by comparing minutes, not raw timestamp seconds

experimenting with 'invalid state' i.e. when timestamp was not generated

include restore logic in tests, as code now lives in .ipp

https://github.com/xoseperez/espurna/issues/1550#issuecomment-2103315452
wait 30s for reconnection, perform status change after timer expires

- allow to specify year, month and day in addition to weekdays and time
  2024-05-15 Monday 00:00 <=> runs *only* on May 15th 2024
  year is optional, 05-15 <=> any May 15th on any year
- last day of month, Nth week, reversed day-of-month (starting from last)
  *-W1 00:00 <==> run at midnight on the first week of month
  01-L2 6:00 <==> run at six, but only on the second to last day of January
  05-L 12:00 <==> run at twelve, but only on the last day of May
- allow multiple time settings per schedule specified as ranges
  12,13,14:00 <=> run at 12:00, 13:00 and 14:00
  Friday..Sunday 12:00 <=> run at 12:00, but only only on Friday, Saturday and Sunday
- similar to weekdays default, allow asterisk (*) to avoid using exact value
  *:30 <=> every hour at 30 minutes
  10:* <=> every minute at 10 o'clock
- repetition value for more control over steps between runs
  *:0/5 <==> every 5 minutes, starting with 0
  0/2:00 <==> every 2 hours, starting with 0

- rework api and settings storage to use 1 key for time setting
  type and 'enabled' state moved into one
- implement sunrise & sunset suggested in #2417
  should be specified instead of HH:MM

note that there is an issue with overload resolution, since template
requires serilize() to be available *before template* and not at the
point of the caller.

serialize converted to template should fix it, though

everything related to calendar time vs. system one
no need to include ntp for formatting, too

separate search and value retrieval