fix(daemon): create --save-token directory when not exist

[hanabi1224]

Summary of changes

Changes introduced in this pull request:

• create --save-token directory when not exist
• improve error message

Reference issue to close (if applicable)

Closes #5233

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

[LesnyRumcajs]

Let's cover it in tests, perhaps extending this:

forest/tests/keystore_tests.rs

Lines 54 to 79 in 8191e94

	#[test]
	fn should_create_jwt_admin_token() {
	let (config_file, data_dir) = create_tmp_config();
	let token_path = data_dir.path().join("admin-token");
	daemon()
	.common_args()
	.arg("--config")
	.arg(config_file)
	.arg("--encrypt-keystore")
	.arg("false")
	.arg("--save-token")
	.arg(&token_path)
	.assert()
	.success();
	// Grab the keystore and the private key
	let keystore = KeyStore::new(KeyStoreConfig::Persistent(data_dir.path().to_owned())).unwrap();
	let key_info = keystore.get(JWT_IDENTIFIER).unwrap();
	let key = key_info.private_key();
	// Validate the token
	assert!(token_path.exists());
	let token = std::fs::read_to_string(token_path).unwrap();
	let allow = verify_token(&token, key).unwrap();
	assert!(allow.contains(&"admin".to_owned()));
	}

[hanabi1224]

Let's cover it in tests, perhaps extending this:

@LesnyRumcajs test updated