Add capability for datetimeutils to check BST dates from API

[sjefferson99]

Date time utils checks for BST using a static list as Micropython doesn't have a full datetime library.
This may cause failures once the list is exhausted.

Add capability for datetimeutils to query "http://worldtimeapi.org/api/timezone/Europe/London" and cache the dates returned from response:

{
"utc_offset": "+01:00",
"timezone": "Europe/London",
"day_of_week": 0,
"day_of_year": 222,
"datetime": "2025-08-10T12:27:00.431802+01:00",
"utc_datetime": "2025-08-10T11:27:00.431802+00:00",
"unixtime": 1754825220,
"raw_offset": 0,
"week_number": 32,
"dst": true,
"abbreviation": "BST",
"dst_offset": 3600,
"dst_from": "2025-03-30T01:00:00+00:00",
"dst_until": "2025-10-26T01:00:00+00:00",
"client_ip": "145.40.187.65"
}

Build in robust retry logic, the API can be overloaded.

Have the query cache the result in a local file for the year and execute this query if the BST method cannot find a valid year in the static list or file cache.

HID module should run a BST check on start-up to ensure a valid time can be returned when needed (prevents alarms sounding unnecessarily etc).

[sam57719]

Have a config option for timezone as well :)

[sjefferson99]

Could add a config option for timezone (link to standard zone definitions) and have a util function to calculate localtime, but would be a new issue as not yet needed and separate development although using the same API, would depend on this one.