Elixir: Not all functions are properly identified

Describe the bug
In addition to #245, there are two other function declarations that are currently not correctly identified by @function.inner/@function.outer queries. The following are not matched:

def foo(), do: 12
def foo() do
  12
end

def guarded_fn(a, b) when a == b, do: a + b
def guarded_fn(a, b) when a != b do
  a * b
end

To Reproduce
Steps to reproduce the behavior:

1. Add above code to editor
2. Try to move to next/prev function.

Expected behavior
Functions with guards and functions without parameters are correctly identified.

Additional context

Reproduce the examples in an editor and inspect the @function.inner and @function.outer queries that handle Elixir functions. Compare declarations with and without parameters and with guards, then verify that moving to the next or previous function identifies all four forms.