Add new acceptance test scenario (015)

```
  Error:
    × Main thread panicked.
    ├─▶ at crates/lang/src/uplc.rs:2388:21
    ╰─▶ not yet implemented
  ```

examples/acceptance_tests/015/aiken.toml

@@ -0,0 +1,2 @@
+name = "acceptance_test_015"
+version = "0.0.0"

examples/acceptance_tests/015/lib/test.ak

@@ -0,0 +1,11 @@
+pub opaque type Map<key, value> {
+  inner: List<#(key, value)>,
+}
+
+pub fn new() {
+  Map { inner: [] }
+}
+
+test new_1() {
+  new() == Map { inner: [] }
+}