NEXT-36108 NewsletterSubscribe add salesChannelId filter

[wexoag]

[NEXT-0000] Update getNewsletterRecipient to search for specific recipient from salesChannelId

1. Why is this change necessary?

Once a newsletter recipient exists on one salesChannel it possible that the wrong recipient is selected, and dispatched along with NewsletterConfirmEvent and NewsletterRegisterEvent in NewsletterSubscribeRoute

2. What does this change do, exactly?

Add salesChannelId filter to select newsletter recipient for the correct salesChannel

3. Describe each step to reproduce the issue or behaviour.

Add event listender for NewsletterConfirmEvent (dd) or something else to show salesChannelId.
Sign up for newsletter on one salesChannel then on another.

4. Please link to the relevant issues (if any).

5. Checklist

• I have rebased my changes to remove merge conflicts
• I have written tests and verified that they fail without my change
• I have created a changelog file with all necessary information about my changes
• I have written or adjusted the documentation according to my changes
• This change has comments for package types, values, functions, and non-obvious lines of code
• I have read the contribution requirements and fulfil them.

[github-actions]

	Warnings
⚠️	The Pull Request doesn't contain any changelog file

[shopware-github-importer]

Hello,

thank you for creating this pull request.
I have opened an issue on our Issue Tracker for you. See the issue link: https://issues.shopware.com/issues/NEXT-36108

Please use this issue to track the state of your pull request.

[bschulzebaek]

Hey @wexoag, thanks for your contribution! We've just merged it 💙