Fix computeInverseAndDetWithCheck for dynamic result matrices

Summary

• Resize the inverse output matrix before computing, so that passing a dynamic-sized matrix (e.g. MatrixXd) as the result of a fixed-size source (e.g. Matrix3d) works correctly instead of failing at runtime
• Add EIGEN_STATIC_ASSERT_SAME_MATRIX_SIZE to catch incompatible fixed-size mismatches at compile time
• Remove redundant assertion from computeInverseWithCheck (already checked in the delegated call)
• Add tests verifying dynamic result matrices are correctly resized for both computeInverseAndDetWithCheck and computeInverseWithCheck

Closes #2917 (closed)