Separate wasmi and wasmer sandbox implementations into their own modules

client/executor/common/src/error.rs

@@ -34,6 +34,9 @@ pub enum Error {
 	#[error(transparent)]
 	Wasmi(#[from] wasmi::Error),
 
+	#[error("Sandbox error: {0}")]
+	Sandbox(String),
+
 	#[error("Error calling api function: {0}")]
 	ApiError(Box<dyn std::error::Error + Send + Sync>),