Capture referenced bindings in anonymous functions

[fuelen]

Describe the bug
Spark doesn't capture referenced bindings in generated functions.

To Reproduce

        presets do
          for {name, message} <- [{:bend, "stuff"}, {:start_casino, "with fun stuff"}] do
            preset name do
              default_message(message)

              contacter(fn message1 ->
                "#{message1}: #{unquote(message)}"
              end)
            end
          end
        end

error:

** (CompileError) test/dsl_test.exs:74: undefined function message/0 (there is no such import)

Expected behavior
Presence of referenced bindings in anonymous functions should generate different anonymous functions depending on the actual value of the binding.

Runtime

• Spark version: latest

Additional context
Link to conversation in Discord.