refactor: [IOPLT-1964] collapsed Overlay component in LoadingSpinnerOverlay

[LeleDallas]

Short description

This pull request refactors the overlay logic in the app by removing the deprecated Overlay component and inlining its behavior directly into LoadingSpinnerOverlay. The change simplifies the codebase, consolidates overlay logic, and updates related tests and snapshots to reflect the new implementation.

List of changes proposed in this pull request

• Removed the deprecated Overlay component and its tests, and moved overlay logic directly into LoadingSpinnerOverlay, simplifying the component structure
• Updated LoadingSpinnerOverlay.tsx to use internal styles and a View-based overlay instead of the Overlay component, and improved overlay styling for better maintainability
• Update snaps

How to test

LoadingSpinnerOverlay render logic should be the same

[github-actions]

PR Title Validation for conventional commit type

✅ All good! PR title follows the conventional commit type.

[github-actions]

Jira Pull Request Link

This Pull Request refers to Jira issues:

• IOPLT-1964

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.91%. Comparing base (addf732) to head (31a4695).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8317      +/-   ##
==========================================
- Coverage   62.92%   62.91%   -0.01%     
==========================================
  Files        1963     1962       -1     
  Lines       37271    37265       -6     
  Branches     6290     6287       -3     
==========================================
- Hits        23452    23446       -6     
  Misses      12436    12436              
  Partials     1383     1383              

Files with missing lines	Coverage Δ
...s/main-app/ts/components/LoadingSpinnerOverlay.tsx	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

---

Continue to review full report in Codecov by Harness.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update addf732...31a4695. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.