[IMP] compiler: add prop suffix name in the error message

Without this, you only get the following error:
```
UncaughtPromiseError > OwlError
Uncaught promise > Invalid prop suffix
OwlError: Invalid prop suffix
```

Which is not helping much to find the problematic code.

src/compiler/code_generator.ts

@@ -1156,7 +1156,7 @@ export class CodeGenerator {
         case "translate":
           break;
         default:
-          throw new OwlError("Invalid prop suffix");
+          throw new OwlError(`Invalid prop suffix: ${suffix}`);
       }
     }
     name = /^[a-z_]+$/i.test(name) ? name : `'${name}'`;

tests/components/props.test.ts

@@ -339,7 +339,7 @@ test("throw if prop uses an unknown suffix", async () => {
 
   await expect(async () => {
     await mount(Parent, fixture);
-  }).rejects.toThrowError("Invalid prop suffix");
+  }).rejects.toThrowError("Invalid prop suffix: somesuffix");
 });
 
 test(".alike suffix in a simple case", async () => {