Update NeuralAmpModelerCore to v0.5.5 and Eigen to 5.0.1

[sdatkinson]

Summary

• update the NeuralAmpModelerCore submodule from v0.5.3 to the current origin/main release candidate for v0.5.5 (daae2d0)
• update the top-level Eigen submodule to 5.0.1 (bc3b398), matching Core's nested Eigen revision and superseding Update NeuralAmpModelerCore to 0.5.4 and Eigen to 5.0.1 #650
• add the new linear.cpp and nam_file.cpp translation units to the macOS, iOS, and Windows build projects
• add the new compiler.h, linear.h, and nam_file.h headers to project metadata

Impact

The plugin now builds and links against the v0.5.5 Core release candidate with a consistent Eigen 5.0.1 dependency, including the new linear-model and NAM-file validation implementations.

Validation

• macOS standalone app Debug build: passed
• macOS VST3 Debug build: passed
• macOS AU Debug build: passed
• macOS/iOS Xcode project parsing: passed
• Visual Studio project XML validation: passed
• git diff --check: passed
• iOS AUv3 framework build: the new Core sources compile, but the build remains blocked by the pre-existing missing NeuralAmpModeler/projects/resample.cpp reference already present on main