[acl] add migration handler for inter-contract data struct changes (s…

…ei-protocol#134)

## Describe your changes and provide context
Added back old proto definitions in `legacy.proto` to facilitate
migration.
Added a migration handler that iterates through wasm dependency
registrations, decode them with the legacy proto, and overwrite with the
new proto

## Testing performed to validate your change
unit tests

proto/cosmos/accesscontrol/legacy.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+package cosmos.accesscontrol.v1beta1;
+
+import "gogoproto/gogo.proto";
+import "cosmos/accesscontrol/constants.proto";
+import "cosmos/accesscontrol/accesscontrol.proto";
+
+option go_package = "github.com/cosmos/cosmos-sdk/types/accesscontrol";
+
+message LegacyAccessOperationWithSelector {
+    AccessOperation operation = 1;
+    AccessOperationSelectorType selector_type = 2;
+    string selector = 3;
+}
+
+message LegacyWasmDependencyMapping {
+    bool enabled = 1;
+    repeated LegacyAccessOperationWithSelector access_ops = 2 [
+        (gogoproto.nullable) = false
+    ];
+    string reset_reason = 3;
+    string contract_address = 4;
+}