refactor: create and use disk-cache utilities for contracts-cache items

docs/userguides/contracts.md

@@ -178,8 +178,9 @@ or
 ```python
 from ape import project
 
+
 def main():
-  my_contract = project.MyContract.deployments[-1]
+    my_contract = project.MyContract.deployments[-1]
 ```
 
 `my_contract` will be of type `ContractInstance`.

src/ape/api/transactions.py

@@ -73,7 +73,7 @@ def __init__(self, *args, **kwargs):
     @classmethod
     def validate_gas_limit(cls, value):
         if value is None:
-            if not cls.network_manager.active_provider:
+            if not cls.network_manager.connected:
                 raise NetworkError("Must be connected to use default gas config.")
 
             value = cls.network_manager.active_provider.network.gas_limit
@@ -82,7 +82,7 @@ def validate_gas_limit(cls, value):
             return None  # Delegate to `ProviderAPI.estimate_gas_cost`
 
         elif value == "max":
-            if not cls.network_manager.active_provider:
+            if not cls.network_manager.connected:
                 raise NetworkError("Must be connected to use 'max'.")
 
             return cls.network_manager.active_provider.max_gas

src/ape/contracts/base.py

@@ -1054,7 +1054,7 @@ def from_receipt(
 
         # Cache creation.
         creation = ContractCreation.from_receipt(receipt)
-        cls.chain_manager.contracts._local_contract_creation[address] = creation
+        cls.chain_manager.contracts.contract_creations[address] = creation
 
         return instance