Mesh_3 - revert encroachment rule modification, and fix infinite refinement

[janetournois]

Summary of Changes

This PR reverts commit 06d272169feeeb6d4c0ad93d83f0624f1666becd

There may be an inconsistency between exact and inexact computations, in the facet encroachment rule.

The removed code was leading to a local infinite refinement loop in the cells refinement step.

Release Management

• Affected package(s): Mesh_3
• License and copyright ownership: unchanged

[sloriot]

Successfully tested in 6.0-Ic-224