Run code through `clang-format` to normalize formatting

[mhucka]

What is the task?

In order to help contributors use agreed-upon code formatting conventions, we should make sure that the existing code follows a defined format (defined in .clang-format).

(Optional) Do you have ideas or preferences for the approach?

Double-check .clang-format, run clang-format over the code base, and add the merge commit to the .git-blame-ignore-revs file.

How urgent is this for you?

P2 – needed within two quarters