Infrastructure: Benchmarks

[OoLunar]

After a successful build on Github Actions, it is recommended to run Benchmarks and post the results as a comment on the commit. This can help others conveniently determine if their new code negatively affects performance, as comments on commits are sent to Discord via webhook. For benchmark testing, it is recommended to use BenchmarkDotNet, which supports the dotnet test command. Our choice for choosing BenchmarkDotNet should be fairly obvious, however you should checkout their Readme if you're having difficulty understanding why. To organize the code, it is suggested to create a separate benchmarks folder for benchmark tests, and a tests folder for functional tests. Functional testing is not in the scope of this issue and will instead of tackled on a seperate issue or PR.

BenchmarkDotNet should measure the following:

• A complete HTTP request: Receive, parsing, execution and responding.
• Database operations.
• How long GenHTTP takes to parse until our handlers receive. Measuring our dependencies is important when identifying bottlenecks in our code.

The benchmarking should be performed only against Linux, as it is the core "OS" for which the bot is designed. While Windows and Mac support will be offered on a best-effort basis, intentional support for those platforms will not be provided.