The locale state between dialogs and subapps is not kept in sync properly and will lead to inconsistent behavior. This is a problem for authors that frequently switch between languages while editing content.

Steps to reproduce

1. Edit page in pages app:
   1. Subapp locale switcher should show EN
      https://demoauthor.magnolia-cms.com/.magnolia/admincentral#app:pages-app:detail;/travel/about:edit
2. Edit Page Properties
   1. Select DE as Language
   2. Close Dialog through Cancel (or save, doesn't matter)
3. Subapp/Editor page is still showing EN page and locale selection
   1. Select main area
   2. Select Add Component
   3. Select Text and Image
4. Text and Image Component Dialog opens in DE
   1. If saved, the newly created component will have _de properties, but the pages subapp is still in EN view.

Expected results

• Dialogs open up in the locale that is selected in the current subapp

Actual results

• Dialog opens up in the locale last selected in a previous dialog

Development notes

• The locale switcher in a dialog correctly updates the state (LocaleContext) of a subapp
• However, the subapp doesn't listen to changes of its own LocaleContext.
• As a result, the subapp may operate in a different locale than is defined in its own LocaleContext.
• This has wider implications - e.g. all availability rules that operate on the locale, will receive the wrong locale from the subapp -> wrong actions allowed/disallowed in contrast to what the user is seeing