Add new acceptance test scenario (008)

```
  Error:
    × Main thread panicked.
    ├─▶ at crates/lang/src/uplc.rs:530:41
    ╰─▶ not yet implemented
    help: set the `RUST_BACKTRACE=1` environment variable to display a backtrace.
  ```

examples/acceptance_tests/008/aiken.toml

@@ -0,0 +1,2 @@
+name = "acceptance_test_008"
+version = "0.0.0"

examples/acceptance_tests/008/lib/test.ak

@@ -0,0 +1,21 @@
+use aiken/builtin
+
+pub fn is_empty(bytes: ByteArray) -> Bool {
+  builtin.length_of_bytearray(bytes) == 0
+}
+
+test is_empty_1() {
+  is_empty(#[]) == True
+}
+
+test is_empty_1_alt() {
+  is_empty(#[])
+}
+
+test is_empty_2() {
+  is_empty(#[1]) == False
+}
+
+test is_empty_2_alt() {
+  !is_empty(#[1])
+}