Feature: Feature mesh deformation

[Lena-Richter]

Closes #2197

Describe your changes here:
Added mesh deformation support using the new t8_cmesh_mesh_deformation files. This allows moving mesh vertices to new positions defined by a CAD geometry.
The calculation is currently done by focusing on surface vertices and comparing their current locations with the target CAD shape. The displacement for internal vertices is not yet included. A new example, t8_cmesh_mesh_deformation_example.cxx, was added to show how the deformation works.

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General

• The reviewer executed the new code features at least once and checked the results manually.
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Tests

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License

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.59%. Comparing base (4840a9f) to head (161513c).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2196   +/-   ##
=======================================
  Coverage   82.59%   82.59%           
=======================================
  Files         115      115           
  Lines       18545    18545           
=======================================
  Hits        15318    15318           
  Misses       3227     3227           

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[sandro-elsweijer]

almost there!