feat: capability for XML's token

[jkowalleck]

Feature request

Implement a capability (decorator) to mark class properties as normalizedString for XML.
Only when this marker is set:

• on serializing to XML: replace special characters by space ( ), and collapse all spaces afterward
• on deserializing to XML: replace special characters by space ( ), and collapse all spaces afterward

why both? Because the values should not have been in the XML in the first place!
so they must not appear after reading, and they must not appear after writing.

Background

XSD http://www.w3.org/2001/XMLSchema - which defines token as follows:

<xs:simpleType name="token" id="token">
  <xs:annotation>
    <xs:documentation source="http://www.w3.org/TR/xmlschema-2/#token"/>
  </xs:annotation>
  <xs:restriction base="xs:normalizedString">
    <xs:whiteSpace value="collapse" id="token.whiteSpace"/>
  </xs:restriction>
</xs:simpleType>

token represents tokenized strings. The ·value space· of token is the set of strings that do not contain the carriage return (#xD), line feed (#xA) nor tab (#x9) characters, that have no leading or trailing spaces (#x20) and that have no internal sequences of two or more spaces. The ·lexical space· of token is the set of strings that do not contain the carriage return (#xD), line feed (#xA) nor tab (#x9) characters, that have no leading or trailing spaces (#x20) and that have no internal sequences of two or more spaces. The ·base type· of token is normalizedString.

[jkowalleck]

similar to #114

[jkowalleck]

solution as done in TS?JS CycloneDX/cyclonedx-javascript-library#1116

[jkowalleck]

i started working on this, via #119