feat: refactored benchmarks and added CliBenchmarks

[TimothyMakkison]

• Added CliBenchmarks containing benchmarks for formatting a directory and checking a list of files.
  • Uses the CSharpier project to format and check.
  • As Soda found in Improve performance of CLI when passing in files/folders #1893, CSharpier is very bad at handing multiple files, each iteration of CliBench took 50 seconds for me 😑
• Benchmarks is getting cluttered so I split it up into CSharpBenchmarks and XmlBenchmarks

Relevant to #1893

[TimothyMakkison]

Should work, but I'm a little confused.

When I run dotnet csharpier format . at the root of my csharpier repo it takes 3 seconds
Formatted 447 files in 3881ms.

FormatCli should be identical and yet it runs faster than in terminal
Formatted 447 files in 872ms.

I assume this discrepancy is because the method is allowed to warmup beforehand 🤔