This enforces us to remove duplicated code across the SysFS code. This
results in great simplification of how the SysFS works now, because we
enforce one way to treat SysFSDirectory objects.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
