feat(ssh): Add support for ECDSA SSH keys

- Resolve #319

assets/translations/en.json

@@ -83,7 +83,7 @@
         "no_key_name": "Unnamed key",
         "root_title": "These are superuser keys",
         "root_subtitle": "Owners of these keys get full access to the server and can do anything on it. Only add your own keys to the server.",
-        "input_label": "Public ED25519 or RSA key"
+        "input_label": "Public ED25519, ECDSA or RSA key"
     },
     "onboarding": {
         "page1_title": "Digital independence, available to all of us",

lib/logic/cubit/forms/user/ssh_form_cubit.dart

@@ -12,7 +12,7 @@ class SshFormCubit extends FormCubit {
     required this.user,
   }) {
     final RegExp keyRegExp = RegExp(
-      r'^(ssh-rsa AAAAB3NzaC1yc2|ssh-ed25519 AAAAC3NzaC1lZDI1NTE5)[0-9A-Za-z+/]+[=]{0,3}( .*)?$',
+      r'^(ecdsa-sha2-nistp256 AAAAE2VjZH|ssh-rsa AAAAB3NzaC1yc2|ssh-ed25519 AAAAC3NzaC1lZDI1NTE5)[0-9A-Za-z+/]+[=]{0,3}( .*)?$',
     );
 
     key = FieldCubit(