refactor(front): Untangle Front- and Backend

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2039>

changes/changelog.d/serve-frontend-without-middleware.refactoring

@@ -0,0 +1,2 @@
+Instead of requesting the right spa content from the API using a middleware we now serve the
+Frontend directly with nginx and only proxy-forward for API endpoints

deploy/nginx.template

@@ -83,16 +83,17 @@ server {
         text/x-cross-domain-policy;
     # end of compression settings
 
-    location / {
+    location /api/ {
         include /etc/nginx/funkwhale_proxy.conf;
         # This is needed if you have file import via upload enabled.
         client_max_body_size ${NGINX_MAX_BODY_SIZE};
         proxy_pass   http://funkwhale-api/;
     }
 
-    location /front/ {
+    location / {
         alias ${FUNKWHALE_FRONTEND_PATH}/;
         expires 1d;
+        try_files $uri $uri/ /index.html;
     }
 
     location = /front/embed.html {