Review defaults for equality

[dgor82]

See Nutshell p. 344ff

• [ ] -> by default use == for static resolution and performance and default behaviour where-ever possible!
• [ ] Use .Equals or object.Equals() only for explicit reasons like accessing overriden equality or structural equality for reference types that are not records
• [ ] Need to go through my code and change many .Equals back to == due to using it as default after all
• [ ] And document it in my dev style guide!
• [ ] Update pitfall about equality, which recommends .Equals as default (https://github.com/CheckMadeOrga/CheckMade/wiki/Dev-Style-Guide-And-Pitfalls#equality-operators)