Refactor lambda binding and parameter handling

Introduce `BoundKind::Parameter` to represent function parameters.
Modify `Binder` to correctly handle parameters within lambda
definitions, ensuring they are only defined within function scopes.
Update `LambdaCollector` to register the body of lambdas as templates
for global definitions.
Adjust `Dumper` to accurately represent lambda parameters.
Update `Specializer` and `TCO` to handle the new `BoundKind::Parameter`.
Refactor `Call` and `TailCall` to use a single `args` node, often a
tuple.
Adjust type signatures in RTL to use `StaticType::Tuple` for function
parameters.

src/ast/rtl/datetime.rs

@@ -4,7 +4,7 @@ use chrono::{NaiveDate, NaiveDateTime};
 
 pub fn register(env: &Environment) {
     let date_ty = StaticType::Function(Box::new(Signature {
-        params: vec![StaticType::Text],
+        params: StaticType::Tuple(vec![StaticType::Text]),
         ret: StaticType::DateTime
     }));