Add an InducedMetric class in mito/geometry

[Pawel024]

This pull request introduces the InducedMetric class, a geometric abstraction for computing metrics on submanifolds embedded in arbitrary coordinate systems and ambient dimensions.

Key changes:

• New InducedMetric class that computes the induced metric tensor g_induced = J^T * g_ambient * J and its inverse
• Volume element support with via sqrt(det(g_induced))
• Support for contravariant gradients (both vector and scalar) in ambient space via J * (g_inv_induced * dphi_dxi)
• Volume form support via w = sqrt(det(g_induced)) * (dx^0 ∧ ... ∧ dx^(N-1))
• New tests, validating metric computation, gradient consistency, and volume element calculations for:
  • segments embedded in 1D, 2D, and 3D coordinate systems
  • triangles embedded in 2D and 3D coordinate systems