Set lower default value for maximumLength in TextInput and TextArea

To avoid flood memory in input fields, the default value for maximumLength (or maximum number of chars) has to be put to a lower value (up to now is was Integer.MAX_VALUE), that could be:
32768 - 1 for TextInput (like in other GUI frameworks), and 1048576 - 1 for TextArea (where many times it's used to display even long multi-line text).

Note that if/when needed, it's always possible to set maximumLength to any positive value up to Integer.MAX_VALUE, using the related setter method.

Verify if implement maximumLength even for Labels (could be useful too) with the same default value of TextInput, or maybe even lower.