Improve SemanticVersion.ToString implementation

[chris-codeflow]

Description

• Correct the SemanticVersion XML comment for the default SemVer ("s") format.
• Align the IFormattable.ToString method signature with the .NET Standard 2.0 implementation.
• Throw FormatException exceptions from ToString instead of ArgumentException.
• Refactor all the ToString tests to use NUnit TestCase attributes.

Related Issue

Fixes #2879

Motivation and Context

The motivation for this PR was to correct the XML documentation for SemanticVersion.ToString (specifically the IFormattable.ToString implementation) and then implement a series of improvements in the general ToString implementation.

How Has This Been Tested?

• Updated and re-ran the unit tests for the SemanticVersion class.
• Added a new test to verify that a FormatException exception is thrown when an unknown format is specified.

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 added tests to cover my changes.
• All new and existing tests passed.

[asbjornu]

Looks like a decent improvement, thanks! Can you please fix the failing tests?

[chris-codeflow]

@asbjornu . The DotNet Format failure is failing on projects in the build folder which I have not changed in my PR, so I suspect the same failures occurred in the last PR.

[arturcic]

@chris-codeflow I will have a look and fix the build formatting, then you should be able to rebase

[arturcic]

@asbjornu seems like the dotnet format that is part of the .net sdk has changed from .net 6.- rc1 to rc2

[arturcic]

@chris-codeflow you can now rebase on top of main

[chris-codeflow]

@arturcic . The rebase onto main has added duplicate commits, as expected. Please do a squash merge for this PR, so we don't pollute the main branch's commit history.

I broke the golden rule of rebasing which is never to rebase a branch that has been published!

[chris-codeflow]

@arturcic and @asbjornu. The Test artifacts in docker (5.0, alpine.3.12-x64) check is still pending, but the step has completed.

[arturcic]

@arturcic and @asbjornu. The Test artifacts in docker (5.0, alpine.3.12-x64) check is still pending, but the step has completed.

I think GitHub is not displaying the status properly, si if @asbjornu agrees we can merge this

[mergify]

Thank you @chris-codeflow for your contribution!