Run astyle to correct indentation to 4 spaces
Using astyle one can apply only very few rules, unlike clang-format. Because of that this MR corrects the indentation before the other stuff gets correctly formatted in follow up MRs.
I have done the formatting using:
astyle --indent=spaces=4 --convert-tabs `find -type f -name '.cpp' -or -name '.cc' -or -name '*.h'`
In the review of the changes some parts felt off/sensitive/unrelated or would be changed by clang-format anyways, those were reverted. A diff between the edited and automatically formatted states can be found here: diff_to_automatic_formatting.diff
I hope this somewhat reviewable.
If there are parts that you feel think be reverted you can feel free to commend, post a diff, push that in a separate commit.
And this also should go into the 21.04 branch to allow the devs to cherry-pick bugfixes whichout too many merge conflicts.