feat(accounts): add Genesis handling (#17802)

Co-authored-by: unknown unknown <unknown@unknown>

proto/cosmos/accounts/v1/genesis.proto

@@ -0,0 +1,31 @@
+syntax = "proto3";
+
+package cosmos.accounts.v1;
+
+option go_package = "cosmossdk.io/x/accounts/v1";
+
+// GenesisState defines the accounts' module's genesis state.
+message GenesisState {
+  // account_number is the latest account number.
+  uint64 account_number = 1;
+  // accounts are the genesis accounts.
+  repeated GenesisAccount accounts = 2;
+}
+
+// GenesisAccount defines an account to be initialized in the genesis state.
+message GenesisAccount {
+  // address is the address of the account.
+  string address = 1;
+  // account_type is the account type of the account.
+  string account_type = 2;
+  // state is the account state represented as a slice of raw key value byte pairs.
+  repeated KVPair state = 3;
+}
+
+// KVPair defines a key value pair.
+message KVPair {
+  // key is the key of the pair.
+  bytes key = 1;
+  // value is the value of the pair.
+  bytes value = 2;
+}