This does *not* refer to the length of the string passed in, or the length of the string currently stored. This refers to the maximum length of the HTML form, and the size of the class buffer to hold the value.

Note that this does *not* change the internal _length name, because the variable is exposed as protected and through friendship with WiFiManager. It is however marked deprecated and can be changed on the next major release.

To clarify that the function returns the *max* possible length, and not the length of the current value.

Deprecating getValueLength for removal on next major release.

In HTML forms names and IDs are two different things. Although this value is applied to both attributes, the form data corresponds to the name, *not* the ID. This causes confusion if we want the name and ID to differ, since we are currently calling the name the ID.

For intercepting the value received from the server in derived classes

Preventing a new default value from being assigned if the max length is set to a negative value

Because this is polymorphic, the destructor needs to be virtual to allow for properly clearing data

This creates better encapsulation, and allows it to be overridden by child classes.

This is unused and awkward because it must be done within the manager class to use the loop parameter, since passing the loop value to the parameter object would be odd. Removing it makes the most sense, although it is technically a breaking change if the user has custom string files.

This makes it possible to declare options at the same time as the radio object, and provides for more flexibility.

No functional change