isValidName method
Checks if the string is a valid name. A valid name shouldn't contain any symbols or special characters.
Example:
print('John'.isValidName()); // true
print('John#Doe'.isValidName()); // false
Implementation
bool isValidName() {
final nameRegExp = RegExp(r'[!@#<>?":_`~;[\]\\|=+)(*&^%\s]');
return !nameRegExp.hasMatch(this);
}