[examples] Add proposition for a new default scene

[bakpaul]

This pr adds a new scene in the Demo folder. This is a proposition for a new default scene.
This works has been started here : https://github.com/bakpaul/TestScenes/tree/main/Experimental and is a joint work between myself and @hugtalbot

The main idea behind this scene is to show a lot of features offered by SOFA:

1. Solvers
   • EigenSimplicialLDLT
   • EigenSparseLU
   • ConstantSparsityPatternSystem
2. BeamAdapter
3. Tetrahedron FEM
4. Hexaedron FEM
5. Lagrangian-based constraints
   • FrictionContactConstraint
   • BilateralLagrangianConstraint
   • LinearSolverConstraintCorrection
   • UncoupledConstraintCorrection
   • PointCollisionModel
   • LineCollisionModel
   • ShpereCollisionModel
6. SparseGridRamificationTopology
7. Rigid bodies (See F) + simple collision model

Having this scene by default would force to build BeamAdapter by default.
The scene work fine when using Qt-based GUI, but mouse interaction crashes the scene when using ImGUI-based GUI.
--> an issue needs to be added in SofaGLFW as soon as this PR is accepted.

[ci-depends-on https://github.com/sofa-framework/Regression/pull/75]

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Reviewers will merge this pull-request only if

• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
• it is more than 1 week old (or has fast-merge label).

[bakpaul]

I was thinking that we could inflate the center of the logo by inflating it using PresureChamberConstraint from SoftRobots plugin. But again, this would require to build it by default. I don't know if we want that.

[bakpaul]

And if we agree to load SofaPython3 by default, we could even add a controller that would for instance control the length of a cable actuator that compresses the O to make it look like an ellipse --> more fun + more features

[alxbilger]

This has not been tested on imgui. I guess this is why it does not work. A work has been started to support all kind of interactions: sofa-framework/SofaGLFW#129

[alxbilger]

Maybe we can also think about improving the visuals? For example, we can add a skybox (see #2678), shaders and shadows.

[bakpaul]

Regarding comments in SOFA-dev meeting: let's add this scene in the Demo folder without changing the default scene for now. But let's keep in mind that we don't want to keep caduceus as the default scene. I'll revert some changes and change the name of the PR.

As a recall, we intend to make it the default scene at one point but two issues are still pending :
1- The need to make BeamAdapter as auto fetched.
2- The need to have a config file allowing to change this default scene on our computer

[bakpaul]

[ci-build][with-all-tests]

[sofabot]

[ci-depends-on] detected during build #6.

To unlock the merge button, you must

• Merge or close Add references for new SofaScene demo Regression#75
  For this build, Regression/ExternalProjectConfig.cmake.in will be edited by builders with
  GIT_REPOSITORY https://github.com/sofa-framework/Regression
  GIT_TAG 371959bd84b6e2da5dac943169d779884623a0c5