Formatting only: run code through scripts/format_all.sh

[mhucka]

Some trivial deviations from clang-format in a small number of files seem to have crept in over time. This meant that running the format check scripts in scripts/ could report changes that are not a contributors' actual changes. To prevent possible confusion to developers and maintainers, this commit:

1. adds the results of running ./scripts/format_all.sh
2. adds a .git-blame-ignore-revs file
3. adds intructions to the contributor instructions to run git config blame.ignoreRevsFile on the file

⚠️ Maintainer notice ⚠️: this PR needs to be merged using the "Create a merge commit" strategy. Using "Squash and Merge" or "Rebase and Merge" will change the commit hash and render the entry in .git-blame-ignore-revs ineffective.