Rename package to mattitja/laravel-plausible-proxy

- Rename Composer package to mattitja/laravel-plausible-proxy and
  namespace to Mattitja\LaravelPlausibleProxy
- Point homepage and links to git.mattitja.se
- Forward only User-Agent and visitor IP (X-Forwarded-For) to Plausible
  instead of all request headers
- Forward all event fields and return Plausible's upstream response
- Accept props as array or JSON string
- Drop Laravel 10, upgrade Larastan to 3 and PHPStan plugins to 2
- Remove broken facade alias and dead autoload paths
- Clean up README, issue template and remove invalid FUNDING.yml

.github/ISSUE_TEMPLATE/config.yml

@@ -1,11 +1,8 @@
 blank_issues_enabled: false
 contact_links:
-  - name: Ask a question
-    url: https://github.com/mattitjaab/laravel-plausible-proxy/discussions/new?category=q-a
-    about: Ask the community for help
-  - name: Request a feature
-    url: https://github.com/mattitjaab/laravel-plausible-proxy/discussions/new?category=ideas
-    about: Share ideas for new features
+  - name: Ask a question or request a feature
+    url: https://git.mattitja.se/Github/laravel-plausible-proxy/issues
+    about: Open an issue in the repository
   - name: Report a security issue
-    url: https://github.com/mattitjaab/laravel-plausible-proxy/security/policy
-    about: Learn how to notify us for sensitive bugs
+    url: mailto:hej@mattitja.se
+    about: Please report security issues privately by email