feat: implement core::error::Error for all errors

Signed-off-by: Florian Hartung <florian.hartung@dlr.de>

Author: florianhartung

src/core/error.rs

@@ -146,6 +146,8 @@ pub enum ValidationError {
     I33IsNegative,
 }
 
+impl core::error::Error for ValidationError {}
+
 impl Display for ValidationError {
     fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
         match self {

src/execution/error.rs

@@ -109,6 +109,15 @@ impl Display for RuntimeError {
     }
 }
 
+impl core::error::Error for RuntimeError {
+    fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
+        match self {
+            RuntimeError::Trap(trap_err) => Some(trap_err),
+            _ => None,
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum TrapError {
     DivideBy0,
@@ -160,6 +169,8 @@ impl Display for TrapError {
     }
 }
 
+impl core::error::Error for TrapError {}
+
 impl From<TrapError> for RuntimeError {
     fn from(value: TrapError) -> Self {
         Self::Trap(value)