scripted-diff: Rename PACKAGE_* variables to CLIENT_*

This change ensures consistent use of the `CLIENT_` namespace everywhere
in the repository.

-BEGIN VERIFY SCRIPT-

ren() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./cmake ./src :\(exclude\)./src/secp256k1 ./test ) ; }

ren PACKAGE_NAME      CLIENT_NAME
ren PACKAGE_VERSION   CLIENT_VERSION_STRING
ren PACKAGE_URL       CLIENT_URL
ren PACKAGE_BUGREPORT CLIENT_BUGREPORT

-END VERIFY SCRIPT-

src/addrman.cpp

@@ -253,7 +253,7 @@ void AddrManImpl::Unserialize(Stream& s_)
         throw InvalidAddrManVersionError(strprintf(
             "Unsupported format of addrman database: %u. It is compatible with formats >=%u, "
             "but the maximum supported by this version of %s is %u.",
-            uint8_t{format}, lowest_compatible, PACKAGE_NAME, uint8_t{FILE_FORMAT}));
+            uint8_t{format}, lowest_compatible, CLIENT_NAME, uint8_t{FILE_FORMAT}));
     }
 
     s >> nKey;