Give panda name, change 'pv' to 'prefix' to keep consistent with ophy…

…d v1 devices

src/ophyd_async/panda/panda.py

@@ -106,8 +106,10 @@ class PandA(Device):
     seq: DeviceVector[SeqBlock]
     pcap: PcapBlock
 
-    def __init__(self, pv: str) -> None:
-        self._init_prefix = pv
+    def __init__(self, prefix: str, name: str = "") -> None:
+        super().__init__(self.name)
+        self._init_prefix = prefix
+        self.set_name(self.name)
         self.pvi_mapping: Dict[FrozenSet[str], Callable[..., Signal]] = {
             frozenset({"r", "w"}): lambda dtype, rpv, wpv: epics_signal_rw(
                 dtype, rpv, wpv