Revise certain clang-format settings

Before applying the big clang-format, we should probably double-check that the settings are (close enough to) what we want. I would suggest at least evaluating the following:

• SortIncludes
  • Currently set to Never. We should enable this, as it's nice for consistency
• IncludeBlocks
  • Currently set to Preserve. We should put this to Regroup so that we have consistent ordering here.
• BreakBeforeBinaryOperators
  • Currently set to None
  • NonAssignment should make things a bit more readable, especially when combined with other settings such as AlignOperands

For reference: https://clang.llvm.org/docs/ClangFormatStyleOptions.html