chore: unit test naming and docs

[jopmiddelkamp]

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)
• I have read the CONTRIBUTING document.
• 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.

[cuongph87]

A few comments:

• It feels like most of the added XML comments are somewhat redundant. I think the docs should be omitted if the method name is descriptive enough. Only add meaningful context that isn't in the method name. What do you think?
• Since we're already modifying a lot of files in this PR, maybe we should also try to get rid of as many warnings as possible. I've added several suggestions, but there are more.
• Just a note: When I open certain files in Rider, I get warning "The file was loaded in a wrong encoding: 'UTF-8'", which caused by added BOM character. But after I remove the BOM and then discard the changes, next time I open the file, it works just fine. Maybe it's just my Rider. But this has only started happening recently.