Base64 decode conflict

[rikwillems]

This module conflicts with other modules that work on base64 encoded widget data. In my project I also base64 encode/decode widgets to add RTE and nested widgets.

This patch fixes the conflict: patch_incorrect_decode_of_value.patch

Your decoder checks for the encodedComponentsData prefix on the whole widget configuration and not on the start of the attribute value. Fix this increases compatibility with other modules.