Feature/addressing gb administrative areas

[i-just]

Description

This PR bumps commerceguys/addressing requirement to ^2.3.0 and drops our dataset for administrative areas for United Kingdom in favour of one that now ships with the library.

• our mechanism was added in this PR: Feature/address subdivisions event #13361
• commerceguys/addressing started shipping with GB counties (administrative areas) in v2.3.0: (see Add administrative areas for Great Britain (GB) commerceguys/addressing#111 (comment))
• this PR drops our version of the GB dataset, but keeps the extra code that allow developers to manipulate the subdivision data
• with the changes in this PR released, there's no need to use EVENT_DEFINE_USED_FIELDS, EVENT_DEFINE_FIELD_LABEL and EVENT_DEFINE_USED_SUBDIVISION_FIELDS events to add counties for United Kingdom unless you want to change the new default behaviour;
• keeping them in shouldn't cause problems, but for clarity it's best to remove if not used for anything beyond what addressing library now offers; I've made the code a bit more defensive in case some fields get duplicated by the use of those events
• custom formatter is no longer necessary for GB in order to show the administrative area (for the record, that mechanism was first added in Allow override of default address formatter #13242)
• the data in addressing library is keyed by ISO codes, while our version was keying by county name;
  • if we were to just remove the data and do nothing about the different keys, those "historic" options would still show in the dropdown, because of this bit of code:

    cms/src/helpers/Cp.php

    Lines 2708 to 2711 in 6804f92

    	// Persist invalid values in the UI
    	if ($value && !isset($options[$value])) {
    	$options[$value] = $value;
    	}

  • other differences between our (old) data and addressing library's (new) data are:
    • City of Bristol -> Bristol, City of
    • City of Edinburgh -> Edinburgh, City of
    • City of London -> London, City of
    • County Durham -> Durham, County
    • The Vale of Glamorgan -> Vale of Glamorgan, The
    • we had "Westmorland and Furness" which is missing from the addressing data; that's because it was created on April 1, 2023 and doesn't have an official ISO code yet (this is mentioned on the issue #111; the other thing we also didn't update)
• a migration has been created to handle those changes;

Related issues