Ajout de check et messages d'erreur

sur les formulaires de connexion et
création d'utilisateur.

Front/skydivelogs-app/src/app/login-user/login-user.component.ts

@@ -31,10 +31,16 @@ export class LoginUserComponent implements OnInit {
   }
 
   ngOnInit() {
-    this.loginForm = this.formBuilder.group({
-      username: ["", Validators.required],
-      password: ["", Validators.required]
-    });
+    this.loginForm = this.formBuilder.group(
+      {
+        username: ["", [Validators.required, Validators.minLength(3)]],
+        password: [
+          "",
+          [Validators.required, Validators.pattern("^[A-Za-z0-9_-]{8,15}$")]
+        ]
+      },
+      { updateOn: "blur" }
+    );
 
     // get return url from route parameters or default to '/'
     this.returnUrl = this.route.snapshot.queryParams["returnUrl"] || "/";