FEAT: File support components testing, cleanup and refactors.

[matthewtoghill]

Description

• Refactor FileService to remove remaining dependency on System.Drawing
• Fix BlobStorageService GetFileType() to use string.ToLower()
  • Add unit tests for GetFileType()
• Add unit tests to FileServiceTests
• Remove duplicate Trait declarations in test classes
• General tidy up
• Update packages

Motivation and Context

#31 replaced System.Drawing implementation, however FileService still had a dependency on System.Drawing for its Size class. As we are not using any specific functionality from the Size class and are just using it to represent data then we can replace it with a tuple.

Other changes in this PR are to:

• fix a bug with the GetFileType method that was not handling strings with uppercase characters properly.
• correct some typos and apply consistent style in some areas
• add unit tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[CesarD]

When #31 was implemented I didn't remove the use of the Size struct because it is part of the framework itself, so no additional dependency was required and was mainly used as a helper class... Just a little context on why it was still there 😉