Standardize connectors + permissioning + new frontend for admin pages + small fixes / improvements (#75)

Introducing permissioning, standardize onboarding for connectors, re-make the data model for connectors / credentials / index-attempts, making all environment variables optional, a bunch of small fixes + improvements.

Co-authored-by: Weves <chrisweaver101@gmail.com>

deployment/data/nginx/app.conf.template.dev

@@ -0,0 +1,56 @@
+upstream app_server {
+    # fail_timeout=0 means we always retry an upstream even if it failed
+    # to return a good HTTP response
+
+    # for UNIX domain socket setups
+    #server unix:/tmp/gunicorn.sock fail_timeout=0;
+
+    # for a TCP configuration
+    # TODO: use gunicorn to manage multiple processes
+    server api_server:8080 fail_timeout=0;
+}
+
+upstream web_server {
+    server web_server:3000 fail_timeout=0;
+}
+
+server {
+    listen 80;
+    server_name ${DOMAIN};
+
+    location ~ ^/api(.*)$ {
+        rewrite ^/api(/.*)$ $1 break;
+
+        # misc headers
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header X-Forwarded-Host $host; 
+        proxy_set_header Host $host;
+
+        # need to use 1.1 to support chunked transfers
+        proxy_http_version 1.1;
+        proxy_buffering off;
+
+        # we don't want nginx trying to do something clever with
+        # redirects, we set the Host: header above already.
+        proxy_redirect off;
+        proxy_pass http://app_server;
+    }
+
+    location / {
+        # misc headers
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header X-Forwarded-Host $host; 
+        proxy_set_header Host $host;
+
+        proxy_http_version 1.1;
+
+        # we don't want nginx trying to do something clever with
+        # redirects, we set the Host: header above already.
+        proxy_redirect off;
+        proxy_pass http://web_server;
+    }
+}