scanner: pass the Enum to the Entry class

So we can compose the fqdn (and possibly do value checks and whatnot)

proto/ei-scanner

@@ -181,14 +181,19 @@ class Entry:
 
     name: str = attr.ib()
     value: int = attr.ib()
+    enum: "Enum" = attr.ib()
     summary: str = attr.ib()
     since: int = attr.ib()
 
     @classmethod
     def create(
-        cls, name: str, value: int, summary: str = "", since: int = 1
+        cls, name: str, value: int, enum: "Enum", summary: str = "", since: int = 1
     ) -> "Entry":
-        return cls(name=name, value=value, summary=summary, since=since)
+        return cls(name=name, value=value, enum=enum, summary=summary, since=since)
+
+    @property
+    def fqdn(self) -> str:
+        return f"{self.enum.fqdn}_{self.name}"
 
 
 @attr.s
@@ -532,7 +537,13 @@ class Protocol(xml.sax.handler.ContentHandler):
             value = int(attrs["value"])
             summary = attrs.get("summary", "")
             since = int(attrs.get("since", 1))
-            entry = Entry.create(name=name, value=value, summary=summary, since=since)
+            entry = Entry.create(
+                name=name,
+                value=value,
+                enum=self.current_message,
+                summary=summary,
+                since=since,
+            )
             try:
                 self.current_message.add_entry(entry)
             except ValueError as e: