feat: add helper methods

[dipinknair]

This PR introduces a Helpers class accessible via app.helpers, providing a convenient API for common Mechanical embedding workflows — geometry and material import, image/animation export, and image display.

Usage example

from ansys.mechanical.core import App
from pathlib import Path

app = App(globals=globals(), log_level="DEBUG")
print(app)

output_dir = Path(app.DataModel.Project.ProjectDirectory)

# Import geometry and materials
app.helpers.import_geometry("path/to/model.pmdb")
app.helpers.import_materials("path/to/materials.xml")

# Export an image of the geometry
app.helpers.export_image(
    obj=app.Model.Geometry,
    file_path=str(output_dir / "geometry.png"),
)

# Export with a different camera view
app.helpers.export_image(
    obj=app.Model.Geometry,
    file_path=str(output_dir / "geometry_front.png"),
)

# Display the exported image inline
app.helpers.display_image(image_path=str(output_dir / "geometry_front.png"))

# Export an animation of a result
app.helpers.export_animation(
    obj=total_deformation,
    file_path=str(output_dir / "deformation.gif"),
)

app.close()

New methods on app.helpers

Method	Description
import_geometry(file_path, ...)	Import a geometry file (.pmdb, .agdb, etc.) with configurable named selections, materials, and coordinate systems
import_materials(file_path)	Import a material database (.xml) into the model
export_image(obj, file_path, ...)	Export a PNG/JPG of any Mechanical tree object at configurable resolution and background
export_animation(obj, file_path, ...)	Export a GIF/MP4 animation of a result object
display_image(image_path, ...)	Display an exported image inline via matplotlib

---

Closes #1487

[github-actions]

The documentation for this pull request will be available at https://mechanical.docs.pyansys.com/pull/1507. Please allow some time for the documentation to be deployed.

[codecov]

Codecov Report

❌ Patch coverage is 92.35294% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.78%. Comparing base (4275f11) to head (f07df5d).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1507      +/-   ##
==========================================
+ Coverage   81.18%   81.78%   +0.60%     
==========================================
  Files          42       43       +1     
  Lines        3109     3267     +158     
==========================================
+ Hits         2524     2672     +148     
- Misses        585      595      +10     

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[RobPasMue]

Pretty cool! Thanks @dipinknair !

[codacy-production]

Not up to standards ⛔

🔴 Issues 14 minor

Alerts:
⚠ 14 issues (≤ 0 issues of at least minor severity)

Results:
14 new issues

Category	Results
Documentation	14 minor

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🟢 Metrics 38 complexity

Metric	Results
Complexity	38

View in Codacy

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