scripted-diff: rename NetPermissionFlags enumerators

- drop redundant PF_ permission flags prefixes
- drop ALL_CAPS naming per https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Renum-caps
- rename IsImplicit to Implicit

-BEGIN VERIFY SCRIPT-
s() { git grep -l "$1" src | xargs sed -i "s/$1/$2/g"; }

s 'PF_NONE'        'None'
s 'PF_BLOOMFILTER' 'BloomFilter'
s 'PF_RELAY'       'Relay'
s 'PF_FORCERELAY'  'ForceRelay'
s 'PF_DOWNLOAD'    'Download'
s 'PF_NOBAN'       'NoBan'
s 'PF_MEMPOOL'     'Mempool'
s 'PF_ADDR'        'Addr'
s 'PF_ISIMPLICIT'  'Implicit'
s 'PF_ALL'         'All'
-END VERIFY SCRIPT-

src/net.h

@@ -402,7 +402,7 @@ public:
     std::unique_ptr<TransportDeserializer> m_deserializer;
     std::unique_ptr<TransportSerializer> m_serializer;
 
-    NetPermissionFlags m_permissionFlags{NetPermissionFlags::PF_NONE};
+    NetPermissionFlags m_permissionFlags{NetPermissionFlags::None};
     std::atomic<ServiceFlags> nServices{NODE_NONE};
     SOCKET hSocket GUARDED_BY(cs_hSocket);
     /** Total size of all vSendMsg entries */