Reformat all files

This runs build_tools/style.fish, which runs clang-format on C++, fish_indent on fish and (new) black on python.

If anything is wrong with the formatting, we should fix the tools, but automated formatting is worth it.

share/functions/__fish_describe_command.fish

@@ -8,7 +8,8 @@ function __fish_describe_command -d "Command used to find descriptions for comma
     # TODO: stop interpolating argv into regex, and remove this hack.
     string match --quiet --regex '^[a-zA-Z0-9_ ]+$' -- "$argv"
     or return
-    type -q apropos; or return
+    type -q apropos
+    or return
     apropos $argv 2>/dev/null | awk -v FS=" +- +" '{
 		split($1, names, ", ");
 		for (name in names)