[Fix] read ReqIF documents without whitespace between elements; fixes #94

[samatstariongroup]

Prerequisites

• I have written a descriptive pull-request title
• I have verified that there are no overlapping pull-requests open
• I have verified that I am following the ReqIFSharp code style guidelines
• I have provided test coverage for my change (where applicable)

Description

Fixes #94.

A ReqIF document without whitespace between its elements (minified XML) lost data without an error. ReadElementContentAsString moves the reader past the end tag, so in a while (reader.Read()) loop the next Read() skipped the following sibling:

• every other ReqIFHeader field (such as CREATION-TIME and REQ-IF-TOOL-ID) was empty;
• every other ENUM-VALUE-REF of an enumeration attribute value was missing;
• the spec relations of a relation group were not read, or an XmlException was thrown.

Changes

• New internal XmlReaderExtensions.ReadElementContentAsStringToEndElement (and ...Async): reads the text content of the element and leaves the reader on its end tag (or on the element when it is empty). It throws an XmlException, with line information when available, when the element contains child elements.
• ReqIFHeader, AttributeValueEnumeration (ENUM-VALUE-REF) and RelationGroup (SPEC-RELATION-REF) use it, sync and async.
• RelationGroup reads SPEC-RELATIONS through a subtree reader instead of ReadStartElement/ReadEndElement. Only direct children are read. A child other than SPEC-RELATION-REF is skipped with a warning and the references after it are read; before, it caused an XmlException. The schema allows only SPEC-RELATION-REF there.
• The other ReadElementContentAs* and ReadInnerXml calls in the library were checked: each reads the only child of a wrapper element or reads through a subtree, and is not affected.

Tests

• MinifiedDocumentTestFixture:
  • minified copies of the test documents read to the same object graph as the originals, as .reqif and .reqifz;
  • every header field of a minified header is read, also after empty fields;
  • a relation group with two spec relations, with SPEC-RELATIONS last and before TYPE, an empty SPEC-RELATIONS, and an unsupported child (warning logged, nested reference not read), indented and minified.
• XmlReaderExtensionsTestFixture: text, CDATA and comments, empty elements, whitespace before the element, child elements, wrong position, and the line information in the exception.
• Shared helpers moved from PrefixedNamespaceTestFixture into TestDocuments.
• All tests run sync and async. dotnet build -c Release: 0 warnings; dotnet test: 436 passed.

Found during the review, tracked separately: #95 (THE-ORIGINAL-VALUE is not read).

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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