Fix docs, config and folder support for tiled ensemble

[blaz-r]

📝 Description

• This PR fixes some bugs within the tiled ensemble code: 1. replaces accelerator value "gpu" in config with "cuda" and also fixes the docs to reflect this correctly. 2. Fixes project root dir naming code to support Folder dataset. 3. Fixes val and test split reading from config file, to enable absence of val/test_split_mode field in config.
• 🛠️ Fixes [Bug]: Tile Pipeline yaml configuration class_path Class Folder not supported #2409

✨ Changes

Select what type of change your PR is:

• 🐞 Bug fix (non-breaking change which fixes an issue)
• 🔨 Refactor (non-breaking change which refactors the code base)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🔒 Security update

✅ Checklist

Before you submit your pull request, please make sure you have completed the following steps:

• 📋 I have summarized my changes in the CHANGELOG and followed the guidelines for my type of change (skip for minor changes, documentation updates, and test enhancements).
• 📚 I have made the necessary updates to the documentation (if applicable).
• 🧪 I have written tests that support my changes and prove that my fix is effective or my feature works (if applicable).

For more information about code review checklists, see the Code Review Checklist.

[codecov]

Codecov Report

Attention: Patch coverage is 76.47059% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.94%. Comparing base (bcc0b43) to head (f091715).

Files with missing lines	Patch %	Lines
...anomalib/pipelines/tiled_ensemble/test_pipeline.py	66.66%	3 Missing ⚠️
...nomalib/pipelines/tiled_ensemble/train_pipeline.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2414      +/-   ##
==========================================
- Coverage   81.96%   81.94%   -0.02%     
==========================================
  Files         283      283              
  Lines       12539    12551      +12     
==========================================
+ Hits        10277    10285       +8     
- Misses       2262     2266       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests