Paywall block: logged-out view ignores Site Language

### Impacted plugin

Jetpack

### Quick summary

When you place a Paywall Block, the text on the call to action that non-subscribers see is not editable, and the language doesn't change when [changing the site's default language](https://wordpress.com/support/set-your-sites-language-and-timezone/), it remains defiantly English.

Ideally, I think users should be able to edit this text themselves? But at the very least it should be more intuitive to make it the same language as the rest of the site.

### Steps to reproduce

1. [set up paid newsletters](https://wordpress.com/support/paid-newsletters/#use-the-paywall-block) on a site with the language set to anything other than English (or set your site's language to something else temporarily for testing)
2. place the Paywall block on a post
3. check the post on the front end and see the chunk of English text that sticks out like the proverbial sore thumb

### A clear and concise description of what you expected to happen.

paywall text should be the same language as the rest of the site

### What actually happened

I did eventually find that [changing your account's _Interface_ Language](https://wordpress.com/support/account-settings/#interface-language) does translate the text, but this is far from intuitive, especially considering that we state explicitly in our documentation that "This is the language you will see as you use WordPress.com. It does not change the language that others see when they access your WordPress.com site."

### Impact

All

### Available workarounds?

Yes, difficult to implement

### Platform (Simple and/or Atomic)

Simple, Atomic

### Logs or notes

_No response_

Start by tracing the Paywall Block's logged-out call-to-action and how it selects the site language versus the account Interface Language. Reproduce the issue on a non-English Simple or Atomic site, then verify that the displayed paywall text follows the site's language and remains correct on the front end.

Written by the indexing model from the issue text.