Add database configuration via command-line arguments

A new configuration setup now allows specifying a path for database properties via command-line arguments during application startup. This update also changes the call signature for `DatabaseConnection.initialize()` method to accept a path argument. Similarly, methods in `PropertiesLoader`, `PropertiesWriter`, and `MailSettings` classes were also updated to use the specified path when working with properties files. The `TestForm` class's tests were updated accordingly to handle these changes.

src/test/java/TestForm.java

@@ -15,7 +15,7 @@ public class TestForm {
 
     @BeforeAll
     public static void testInsert() {
-        Assertions.assertDoesNotThrow(DatabaseConnection::initialize);
+        Assertions.assertDoesNotThrow(() -> DatabaseConnection.initialize());
         StoreFormQuery storeFormQuery = new StoreFormQuery();
         ContactFormData contactFormData = new ContactFormData("akastijn", "[email protected]", "This is a test question.");
         storeFormQuery.storeFormForVerificationCode("[email protected]", contactFormData).
@@ -28,7 +28,7 @@ public class TestForm {
 
     @Test
     public void testRetrieveForm() {
-        Assertions.assertDoesNotThrow(DatabaseConnection::initialize);
+        Assertions.assertDoesNotThrow(() -> DatabaseConnection.initialize());
         new FormQuery().getFormForCode(String.valueOf(code), "[email protected]").thenAccept(result -> {
             Assertions.assertTrue(result.failReason().isEmpty());
             Optional<Form> optionalForm = result.form();