[Supplier] chore: improve supplier not found error message (#183)

* chore: improve error message seen by RPC consumers when the given supplier isn't on-chain

* fix: query supplier test

* chore: add todo comment

x/supplier/keeper/query_supplier.go

@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/cosmos/cosmos-sdk/store/prefix"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -52,7 +53,9 @@ func (k Keeper) Supplier(goCtx context.Context, req *types.QueryGetSupplierReque
 		req.Address,
 	)
 	if !found {
-		return nil, status.Error(codes.NotFound, "not found")
+		// TODO_TECHDEBT(#181): conform to logging conventions once established
+		msg := fmt.Sprintf("supplier with address %q", req.GetAddress())
+		return nil, status.Error(codes.NotFound, msg)
 	}
 
 	return &types.QueryGetSupplierResponse{Supplier: val}, nil

x/supplier/keeper/query_supplier_test.go

@@ -47,7 +47,7 @@ func TestSupplierQuerySingle(t *testing.T) {
 			request: &types.QueryGetSupplierRequest{
 				Address: strconv.Itoa(100000),
 			},
-			err: status.Error(codes.NotFound, "not found"),
+			err: status.Error(codes.NotFound, "supplier with address \"100000\""),
 		},
 		{
 			desc: "InvalidRequest",