[WIP] Add ExpandWildcardImportsStep with custom classpath

[Copilot]

Implementation Plan for Issue diffplug#2829: Expand Wildcard Imports for Maven Plugin

• Explore repository structure and understand current implementation
• Understand how ForbidWildcardImportsStep currently works (it's a lint-only step)
• Understand how FormatterStepConfig and FormatterStepFactory architecture works
• Found existing ExpandWildcardImportsStep implementation from PR new step to expand java wildcard imports diffplug/spotless#2744
• Extend FormatterStepConfig to include optional project classpath
• Extend FormatterConfig to include Maven project reference
• Modify FormatterFactory to provide protected method for classpath extraction
• Override getProjectClasspath() in Java formatter factory to extract compile+test classpath
• Create ExpandWildcardImports Maven plugin configuration class
• Add method to Java formatter factory to register the new step
• Test the implementation with a sample Maven project
• Add tests for the new functionality
• Update Maven plugin documentation
• Verify changes don't break existing tests

Original prompt

I want to implement @diffplug/spotlessdiffplug/issues/2829

the main problem is that the ExpandWildcardImportsStep needs a Set typeSolverClasspath for the java parser to resolve dependencies

i can create the typeSolverClassPath from maven project using project.getCompileClasspathElements etc but i dont understand how to pass that to the FormatterStepFactory that will create the ExpandWildcardImportsStep

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