[IgaApplication] example with SBM in 2d with convergence study importing a nurbs

[NickNick9]

First Example of an SBM-IGA Application for 2D Solid Elements

This pull request introduces a first benchmark example demonstrating the use of the Shifted Boundary Method (SBM) in combination with Isogeometric Analysis (IGA) for 2D solid elements.

The following features are included:

✅ A convergence study to validate the numerical accuracy of the method.

📈 Plots of the surrogate boundary to illustrate the geometry approximation.

📍 Pointwise error analysis, comparing the computed solution against the exact solution.

Feedback and suggestions are welcome to improve the clarity and robustness of the example.

[NickNick9]

waiting for some Kratos PRs to be approved, then this test will work