We should do a one-time reformat that brings all existing code into line with the agreed style. The deterministic changes will be applied with dotnet format and contain no behaviour changes and could be split into smaller changes to be more easily reviewed.

We also need to enable the recommended set of rules with <AnalysisMode>Recommended</AnalysisMode>.

Each reformat commit is added to .git-blame-ignore-revs so it doesn't pollute blame.