Add a new host function for reporting fatal errors; make WASM backtraces readable when printing out errors (#10741)

* Add a new host function for reporting fatal errors

* Fix one of the wasmtime executor tests

* Have `#[runtime_interface(wasm_only)]` actually mean WASM-only, and not no_std-only

* Print out errors through `Display` instead of `Debug`

* Switch one more trait to require `Error` for its error instead of only `Debug`

* Align to review comments

substrate/client/consensus/common/src/import_queue/basic_queue.rs

@@ -303,11 +303,11 @@ impl<B: BlockT> BlockImportWorker<B> {
 				.map_err(|e| {
 					debug!(
 						target: "sync",
-						"Justification import failed with {:?} for hash: {:?} number: {:?} coming from node: {:?}",
-						e,
+						"Justification import failed for hash = {:?} with number = {:?} coming from node = {:?} with error: {}",
 						hash,
 						number,
 						who,
+						e,
 					);
 					e
 				})