See #30189.

The current catalog only provides spheres of dimension two. A comprehensive and faster version will be added here.

Features:

• spherical and stereographic coordinates
• orientation
• radius and barycenter can be stated
• link to minimal triangulation in homology module
• initialized embedding such that extrinsic quantities can be derived

Follow-Ups:

• make S^1, S^3 and S^7 parallelizable
• Hopf coordinates on S^3
• link to Lie group structure on S^1 and S^3

CC: @egourgoulhon @tscrim @tobiasdiez

Component: manifolds

Author: Michael Jung

Branch: caa9d5f

Reviewer: Eric Gourgoulhon, Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/30804