Complete project Algorithms - Switch to file-scoped namespace

[gmottajr]

Issue 425 - Migrate to DotNet 8 - File-scoped namespaces:

Algorithms --> Sorters and Strings.

Motivation and Context

Github issue https://github.com/TheAlgorithms/C-Sharp/issues/425: Proposed to update to File-scoped namespaces. It was requested to perform the changes in a few PRs to make them smaller and easier to review. This is the one only meant to update .NET version.

• [x] I have performed a self-review of my code
• [x] My code follows the style guidelines of this project
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Comments in areas I changed are up to date
• [ ] I have added comments to hard-to-understand areas of my code
• [ ] I have made corresponding changes to the README.md

[codecov[bot]]

Codecov Report

Attention: 20 lines in your changes are missing coverage. Please review.

Comparison is base (691d270) 94.42% compared to head (965d7ef) 94.48%.

Files	Patch %	Lines
Algorithms/Sorters/Comparison/TimSorter.cs	94.09%	12 Missing and 6 partials :warning:
Algorithms/Strings/Similarity/JaroSimilarity.cs	94.87%	0 Missing and 2 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #433 +/- ## ========================================== + Coverage 94.42% 94.48% +0.06% ========================================== Files 234 234 Lines 9843 9843 Branches 1455 1455 ========================================== + Hits 9294 9300 +6 + Misses 387 384 -3 + Partials 162 159 -3 ```

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