Authorize complete patterns as function args.

This is mainly a syntactic trick/sugar, but it's been pretty annoying
  to me for a while that we can't simply pattern-match/destructure
  single-variant constructors directly from the args list. A classic
  example is when writing property tests:

  ```ak
  test foo(params via both(bytearray(), int())) {
    let (bytes, ix) = params
    ...
  }
  ```

  Now can be replaced simply with:

  ```
  test foo((bytes, ix) via both(bytearray(), int())) {
    ...
  }
  ```

  If feels natural, especially coming from the JavaScript, Haskell or
  Rust worlds and is mostly convenient. Behind the scene, the compiler
  does nothing more than re-writing the AST as the first form, with
  pre-generated arg names. Then, we fully rely on the existing
  type-checking capabilities and thus, works in a seamless way as if we
  were just pattern matching inline.

crates/aiken-project/src/test_framework.rs

@@ -507,10 +507,8 @@ impl Prng {
         fn as_prng(cst: &PlutusData) -> Prng {
             if let PlutusData::Constr(Constr { tag, fields, .. }) = cst {
                 if *tag == 121 + Prng::SEEDED {
-                    if let [
-                        PlutusData::BoundedBytes(bytes),
-                        PlutusData::BoundedBytes(choices),
-                    ] = &fields[..]
+                    if let [PlutusData::BoundedBytes(bytes), PlutusData::BoundedBytes(choices)] =
+                        &fields[..]
                     {
                         return Prng::Seeded {
                             choices: choices.to_vec(),
@@ -1089,11 +1087,9 @@ impl TryFrom<TypedExpr> for Assertion<TypedExpr> {
                 final_else,
                 ..
             } => {
-                if let [
-                    IfBranch {
-                        condition, body, ..
-                    },
-                ] = &branches[..]
+                if let [IfBranch {
+                    condition, body, ..
+                }] = &branches[..]
                 {
                     let then_is_true = match body {
                         TypedExpr::Var {
@@ -1512,14 +1508,13 @@ mod test {
             }
         "#});
 
-        assert!(
-            prop.run::<()>(
+        assert!(prop
+            .run::<()>(
                 42,
                 PropertyTest::DEFAULT_MAX_SUCCESS,
                 &PlutusVersion::default()
             )
-            .is_success()
-        );
+            .is_success());
     }
 
     #[test]