[ty] More sensible sorting for results returned by `all_symbols`
Previously, we would only sort by name and file path (unless the symbol
refers to an entire module). This led to somewhat confusing ordering,
since the file path is absolute and can be anything.
Sorting by module name after symbol name gives a more predictable
ordering in common practice.
This is mostly just an improvement for debugging purposes, i.e., when
looking at the output of `all_symbols` directly. This mostly shouldn't
impact completion ordering since completions do their own ranking.
