Fix multi-tenant organiser logos in emails with fallback to Hi.Events…

[scracha]

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What changes I've made

Fix #1238 broken uploadimages via volume block (appdata) in docker config. #1238

Updated code in message.blade.php to choose the event organizer name and logo before falling back to VITE_APP_NAME and the Hi.Events logo.

Why I've made these changes

Uploaded images were resulting in broken links to end users.
Hi.Events logo was shown at the top of every email.

How I've tested these changes

Restarting docker to ensure changes are permanent. Testing with multiple browsers with cache refreshed.

Checklist

• I have read the contributing guidelines.
• My code follows the coding standards of the project.
• I have tested my changes, and they work as expected.
• I understand that this PR will be closed if I do not follow the contributor guidelines and if this PR template is left unedited.

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[scracha]

I have read the CLA Document and I hereby sign the CLA