feat: allow editing org icon (#13547)

coderd/database/dump.sql

@@ -595,7 +595,8 @@ CREATE TABLE organizations (
     created_at timestamp with time zone NOT NULL,
     updated_at timestamp with time zone NOT NULL,
     is_default boolean DEFAULT false NOT NULL,
-    display_name text NOT NULL
+    display_name text NOT NULL,
+    icon text DEFAULT ''::text NOT NULL
 );
 
 CREATE TABLE parameter_schemas (