Add support for nested functions with the same name in different contexts

[fur] / examples / 31_nested_functions_same_name.fur

def get_incrementer(n) do
  def foo(m) do
    m + n
  end

  foo
end

def get_multiplier(n) do
  def foo(m) do
    m * n
  end

  foo
end

print(get_incrementer(2)(3), '\n')
print(get_multiplier(2)(3), '\n')