Navigation and intellisense for xs:include-ed types

[angelozerr]

Navigation and intellisense for xs:include-ed types

See redhat-developer/vscode-xml#188

Signed-off-by: azerr azerr@redhat.com

[angelozerr]

This PR gives the capability to support xs:include schema location:

• for definition
• for completion

Test has been written for that. As highlight use the same search code thandefinition and completion, I had to disable search with xs:include for highlight to avoid return the range of xs:element coming from the xs:include XML Schema because LSP highlighting support higlight only for one file and not for external file.

To test this PR, you can use SchemaA.xsd:

<?xml version="1.0" encoding="utf-8" ?>
<xs:schema id="tns" xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
	<xs:include schemaLocation="SchemaB.xsd" />
  
	<xs:complexType name="Bar">
		<xs:sequence>
			<xs:element name="FooBar" type="xs:string" />
			<xs:element ref="TypeFromB" />
			<xs:element ref="TypeFromC" />
		</xs:sequence>
	</xs:complexType>

	<xs:complexType name="Root">
		<xs:sequence>
			<xs:element name="Bar" type="Bar" minOccurs="1" maxOccurs="unbounded" />
		</xs:sequence>
	</xs:complexType>

	<xs:element name="Root" type="Root"></xs:element>
</xs:schema>

which includes XSD SchemaB.xsd which include SchemaC.xsd.

Here a demo:

[NikolasKomonen]

@angelozerr works great, ready to merge!

[angelozerr]

Thanks @NikolasKomonen for your review!