Tweak formatters comparison % match; add syncing tests

- Add tests for ``syncing`` eth_subscribe requests
- Tweak formatters keyset match to 75% match. Across all eth_subscribe requests, the keys are not close to being similar so we can afford a more relaxed check here.

Author: fselmo

web3/_utils/method_formatters.py

@@ -643,13 +643,13 @@ def subscription_formatter(value: Any) -> Union[HexBytes, HexStr, Dict[str, Any]
                 result_formatter = block_formatter
 
             elif either_set_is_a_subset(
-                result_key_set, set(LOG_ENTRY_FORMATTERS.keys()), percentage=90
+                result_key_set, set(LOG_ENTRY_FORMATTERS.keys()), percentage=75
             ):
                 # logs
                 result_formatter = log_entry_formatter
 
             elif either_set_is_a_subset(
-                result_key_set, set(TRANSACTION_RESULT_FORMATTERS.keys()), percentage=90
+                result_key_set, set(TRANSACTION_RESULT_FORMATTERS.keys()), percentage=75
             ):
                 # newPendingTransactions, full transactions
                 result_formatter = transaction_result_formatter
@@ -663,7 +663,7 @@ def subscription_formatter(value: Any) -> Union[HexBytes, HexStr, Dict[str, Any]
             elif either_set_is_a_subset(
                 result_key_set,
                 set(SYNCING_FORMATTERS.keys()),
-                percentage=90,
+                percentage=75,
             ):
                 # syncing response object
                 result_formatter = syncing_formatter

web3/_utils/module_testing/persistent_connection_provider.py

@@ -238,12 +238,50 @@ class PersistentConnectionProviderTest:
                     }
                 ),
             ),
+            (
+                ("syncing",),
+                {
+                    "jsonrpc": "2.0",
+                    "method": "eth_subscription",
+                    "params": {
+                        "subscription": "0x28d37f96bc784de4abf96ee4f8005a79",
+                        "result": False,
+                    },
+                },
+                False,
+            ),
+            (
+                ("syncing",),
+                {
+                    "jsonrpc": "2.0",
+                    "method": "eth_subscription",
+                    "params": {
+                        "subscription": "0x28d37f96bc784de4abf96ee4f8005a79",
+                        "result": {
+                            "isSyncing": True,
+                            "startingBlock": "0x0",
+                            "currentBlock": "0x4346fe",
+                            "highestBlock": "0x434806",
+                        },
+                    },
+                },
+                AttributeDict(
+                    {
+                        "isSyncing": True,
+                        "startingBlock": 0,
+                        "currentBlock": 4409086,
+                        "highestBlock": 4409350,
+                    }
+                ),
+            ),
         ),
         ids=[
             "newHeads",
             "newPendingTransactions-FullTxs",
             "newPendingTransactions-TxHashes",
             "logs",
+            "syncing-False",
+            "syncing-True",
         ],
     )
     async def test_async_eth_subscribe_mocked(