Add support for complex data injection in @MojoParameter for unit testing

[gnodet]

This PR enhances the @MojoParameter annotation to support injection of complex data types when unit testing mojos, with comprehensive test coverage.

Key Features

1. Added xml attribute to @MojoParameter annotation

• xml=true (default): Parse value as XML content (existing behavior)
• xml=false: Treat value as plain text, escaping XML special characters
• Enables comma-separated lists and values with special characters

2. Updated MojoExtension to handle the xml flag

• When xml=true, value is parsed as XML elements
• When xml=false, value is escaped and treated as plain text
• Properly handles special characters like <, >, &, etc.

3. Comprehensive unit tests (15 new tests)

Covering:

• List<String> with XML format
• List<String> with comma-separated format using xml=false
• String[] arrays with both XML and comma-separated formats
• Map<String, String> with XML format
• Properties with XML format
• Custom bean objects with nested properties
• Primitive types (int, boolean)
• Special characters in values with xml=false

4. Fixed plugin.xml type declarations

• Changed from java.lang.List<java.lang.String> (HTML-encoded)
• To java.util.List (proper Maven plugin descriptor format)
• Maven's plugin descriptor doesn't support parameterized types in <type>
• Added proper type declarations for Map, Properties, arrays, and custom beans

Testing

All tests pass successfully (22 tests in maven-testing module).

Example Usage

// Comma-separated list
@Test
@InjectMojo(goal = "my-goal", pom = "pom.xml")
@MojoParameter(name = "items", value = "one,two,three", xml = false)
public void testCommaSeparatedList(MyMojo mojo) {
    assertEquals(List.of("one", "two", "three"), mojo.items);
}

// XML format (default)
@Test
@InjectMojo(goal = "my-goal", pom = "pom.xml")
@MojoParameter(name = "items", value = "<item>one</item><item>two</item>")
public void testXmlList(MyMojo mojo) {
    assertEquals(List.of("one", "two"), mojo.items);
}

// Complex bean
@Test
@InjectMojo(goal = "my-goal", pom = "pom.xml")
@MojoParameter(name = "config", value = "<host>localhost</host><port>8080</port>")
public void testBean(MyMojo mojo) {
    assertEquals("localhost", mojo.config.host);
    assertEquals(8080, mojo.config.port);
}

---

Pull Request opened by Augment Code with guidance from the PR author

[desruisseaux]

It is a small details (not really important), but the code could be factorized a little bit:

String value = mp.value();
if (!mp.xml()) {
    // Treat as plain text - escape XML special characters
    value = value
            .replace("&", "&")
            .replace("<", "&lt;")
            .replace(">", "&gt;")
            .replace("\"", "&quot;")
            .replace("'", "&apos;");
}
String s = '<' + mp.name() + '>' + value + "</" + mp.name() + '>';

I also replaced strings of 1 character by single characters.