receiver_worker: log processes crashes

Oban cataches crashes to handle job failure and retry,
thus it never bubbles up all the way and nothing is logged by default.
For better debugging, catch and log any crashes.

lib/pleroma/workers/receiver_worker.ex

@@ -50,5 +50,12 @@ def perform(%Job{args: %{"op" => "incoming_ap_doc", "params" => params}}) do
         Logger.error("Unexpected AP doc error: (raw) #{inspect(e)} from #{inspect(params)}")
         {:error, e}
     end
+  rescue
+    err ->
+      Logger.error(
+        "Receiver worker CRASH on #{inspect(params)} with: #{Exception.format(:error, err, __STACKTRACE__)}"
+      )
+
+      {:error, :crash}
   end
 end