Improve the handling of JS language packs with each plugin update

## Feature Description

With each Site Kit update there can be issues with Site Kit reverting to English, despite no change to the users defined language (ie/ Japanese). This occurs since there is a delay of up to one hour for language packs to be updated with each plugin release. There are more details contained in the below trac ticket:
https://meta.trac.wordpress.org/ticket/6188

To mitigate these incidents, consider an in product or other solution that checks a users site language and whether they have the latest stable version of the language pack for their active SK version. The user could be shown a prompt to download and install the latest language page.

**Additional context:**

We don't get a lot of users complaining about this in the support forums, but there are plenty of mentions of these elsewhere, in particular from Japanese users of the plugin. See below examples:
- [Recent Report](https://twitter.com/2525_kana_code/status/1695105430324998596)
- [Recent Report 2](https://twitter.com/axecom/status/1697070373240775004)
- [Recent Report 3](https://twitter.com/hiro20180901/status/1686333658251341824)

**Temporary workaround:**
There are a couple of workarounds a user can apply if they find their Site Kit menu items and strings revert to English. These are mentioned below:
- **Workaround 1**: Users can uninstall and reinstall Site Kit once more. This will force updates to the most recent version of the SK language pack for the users defined language
- **Workaround 2** - [Translation Tools](https://wordpress.org/plugins/translation-tools/) or another plugin that update plugins language packs: you can use a plugin to ensure translations will remain in Japanese.
https://wordpress.org/plugins/translation-tools

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## Acceptance criteria

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## Implementation Brief

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### Test Coverage

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## QA Brief

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## Changelog entry

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Start by reviewing the linked WordPress Trac ticket 6188 and the reported language-pack update delay described in this issue. Define the update flow and acceptance criteria around detecting the user's site language, checking the active Site Kit version's latest stable pack, and presenting an appropriate update prompt.

Written by the indexing model from the issue text.