Make deploying meta tags changes easier

- recently updated the names of some of the metatags that GA4 reads for page views
- but it's possible that the changes to those metatags won't be appearing for a while on a lot of pages, as they probably need republishing first
- so for now let's read either the new or the old metatag (which will contain the same information) and avoid breaking a part of the GA4 tracking
- haven't done the same for the strip dates/postcodes/etc. metatags as I think they're all handled internal to the gem
- follow up to changes made in #4222

app/assets/javascripts/govuk_publishing_components/analytics-ga4/ga4-page-views.js

@@ -34,7 +34,7 @@ window.GOVUK.analyticsGa4.analyticsModules = window.GOVUK.analyticsGa4.analytics
             navigation_page_type: this.getMetaContent('navigation-page-type'),
             navigation_list_type: this.getMetaContent('navigation-list-type'),
             step_navs: this.getMetaContent('stepnavs'),
-            taxonomy_level1: this.getMetaContent('taxonomy_level1'),
+            taxonomy_level1: this.getMetaContent('taxonomy_level1') || this.getMetaContent('themes'),
             taxonomy_main: this.getMetaContent('taxon-slug'),
             taxonomy_main_id: this.getMetaContent('taxon-id'),
             taxonomy_all: this.getMetaContent('taxon-slugs'),
@@ -49,8 +49,8 @@ window.GOVUK.analyticsGa4.analyticsModules = window.GOVUK.analyticsGa4.analytics
             publishing_government: this.removeHyphensAndDowncase(this.getMetaContent('publishing-government') || this.getMetaContent('ga4-publishing-government')),
             political_status: this.getMetaContent('political-status') || this.getMetaContent('ga4-political-status'),
             primary_publishing_organisation: this.getMetaContent('primary-publishing-organisation'),
-            organisations: this.getMetaContent('organisations'),
-            world_locations: this.getMetaContent('world-locations'),
+            organisations: this.getMetaContent('organisations') || this.getMetaContent('analytics:organisations'),
+            world_locations: this.getMetaContent('world-locations') || this.getMetaContent('world-locations'),
 
             /* The existence of a referrer parameter indicates that the page has been dynamically updated via an AJAX request
             and therefore we can use it to set the dynamic property appropriately. This value is used by PA's to differentiate