DMN11 — XSD: modify Import in tLiteralExpression

In XSD, top-level element Import is used to make top-level elements in external DMN, XSD, and possibly other types of files visible to the decision model. Import also is part of tLiteralExpression as a way to import value expressions, but it needs additional information. Propose to give this element a different name and type:
In tLiteralExpression, replace Import with importedValues, type tImportedValues. Add tImportedValues as follows:
<xsd:complexType name="tImportedValues">
<xsd:complexContent>
<xsd:extension base="tImport">
<xsd:sequence>
<xsd:element name="importedElement">
<xsd:complexType>
<xsd:simpleContent>
<xsd:extension base="xsd:string">
<xsd:attribute name="expressionLanguage" type="xsd:anyURI"/>
</xsd:extension>
</xsd:simpleContent>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>

replace Import in tLiteralExpression with importedValues, new type

Revise spec, MM Fig 26, and XSD as directed.