support 128 bit difficulty type

src/page.h

@@ -1291,8 +1291,7 @@ show_block(uint64_t _blk_height)
     // initalise page tempate map with basic info about blockchain
 
     string blk_pow_hash_str = pod_to_hex(get_block_longhash(blk, _blk_height));
-    uint64_t blk_difficulty = core_storage->get_db()
-        .get_block_difficulty(_blk_height).convert_to<uint64_t>();
+    cryptonote::difficulty_type blk_difficulty = core_storage->get_db().get_block_difficulty(_blk_height);
 
     mstch::map context {
             {"testnet"              , testnet},
@@ -1313,7 +1312,8 @@ show_block(uint64_t _blk_height)
             {"delta_time"           , delta_time},
             {"blk_nonce"            , blk.nonce},
             {"blk_pow_hash"         , blk_pow_hash_str},
-            {"blk_difficulty"       , blk_difficulty},
+            {"blk_difficulty_lo"    , (blk_difficulty << 64 >> 64).convert_to<uint64_t>()},
+            {"blk_difficulty_hi"    , (blk_difficulty >> 64).convert_to<uint64_t>()},
             {"age_format"           , age.second},
             {"major_ver"            , std::to_string(blk.major_version)},
             {"minor_ver"            , std::to_string(blk.minor_version)},

src/templates/block.html

@@ -32,7 +32,7 @@
         </tr>
         <tr>
             <td>PoW hash:</td><td>{{blk_pow_hash}}</td>
-            <td>Difficulty:</td><td>{{blk_difficulty}}</td>
+            <td>Difficulty (hi64, lo64):</td><td>{{blk_difficulty_hi}}, {{blk_difficulty_lo}}</td>
             <td></td>
         </tr>
     </table>