Add MySQL initialization script and update Docker configuration

Original error was:
Access denied; you need (at least one of) the SUPER or SYSTEM_VARIABLES_ADMIN privilege(s) for this operation

.github/workflows/test-infrastructure-files.yml

@@ -47,6 +47,8 @@ jobs:
           --health-timeout 5s
         ports:
           - 3306:3306
+        volumes:
+          - ./mysql-init.sql:/docker-entrypoint-initdb.d/init.sql          
     steps:
       - name: Set Database Connection String
         run: |

infrastructure_files/mysql-init.sql

@@ -0,0 +1,2 @@
+GRANT SYSTEM_VARIABLES_ADMIN ON *.* TO 'netbird'@'%';
+FLUSH PRIVILEGES;