Mostly line breaks, one instance of tabs!
For some reason clang-format insists on two spaces before a same-line comment?
(I continue to be unimpressed with super-strict line length limits,
but I continue to believe in automatic styling, so it is what it is)
[ci skip]
This mostly fixes some wrong indents or replaces some stray tab indents.
I excluded alignment on purpose, because we have a whole bunch of code
that goes like
```fish
complete -c foo -n 'some-condition' -l someoption
complete -c foo -n 'some-longer-condition' -l someotheroption
```
and changing it seems like a larger thing and would include more
thrashing.
See #3622.
