Improve PasswordField doc

[glebfox]

Existing page: https://docs.jmix.io/jmix/flow-ui/vc/components/passwordField.html

1. passwordField.getValue().isEmpty() == false can be simplified to !passwordField.getValue().isEmpty().

2. Value description says:

If the value cannot be parsed to String, the default conversion error message appears.

Previously doc says:

The input for passwordField can only be of type String.

~Question: in what cases the value cannot be parsed to String?~ String can be converted to String in any cases.

3. Handlers.

   1. Missing statusChangeHandler
   2. ChangeEvent and InvalidChangeEvent no longer valid

4. Validator code example: String.valueOf(value) is redundant, value is already a String.

5. Elements. Missing prefix and suffix elements.

6. Add revealButtonVisible attribute: wait for https://github.com/jmix-framework/jmix/issues/3206

7. Add css, ariaLabel, ariaLabelBy, focusShortcut common attributes

8. Remove requiredIndicatorVisible, invalid