Consider adding EditorBrowsableState attribute to XML serialization properties

[glopesdev]

In cases where XML serialization does not correctly emit code for serializing a property to/from XML, we have provided extra serialization properties of type string exclusively to provide the relevant conversions (original property is then marked with XmlIgnore attribute).

These properties are really not meant to be used as part of the public API, so it may be useful to mark them with the EditorBrowsableState.Never attribute so they do not show up in code completion or public API docs.