data-source/aws_vpc: Refactor to use keyvaluetags library (#10413)

Reference: #7926

In preparation for provider-wide ignore and default tag logic, here we refactor this resource to use the consistent `keyvaluetags` handling.

Output from acceptance testing:

```
--- PASS: TestAccDataSourceAwsVpc_basic (27.54s)
--- PASS: TestAccDataSourceAwsVpc_ipv6Associated (27.56s)
--- PASS: TestAccDataSourceAwsVpc_multipleCidr (51.12s)
```

aws/data_source_aws_vpc.go

@@ -8,6 +8,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/arn"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
+	"github.com/terraform-providers/terraform-provider-aws/aws/internal/keyvaluetags"
 )
 
 func dataSourceAwsVpc() *schema.Resource {
@@ -176,7 +177,11 @@ func dataSourceAwsVpcRead(d *schema.ResourceData, meta interface{}) error {
 	d.Set("instance_tenancy", vpc.InstanceTenancy)
 	d.Set("default", vpc.IsDefault)
 	d.Set("state", vpc.State)
-	d.Set("tags", tagsToMap(vpc.Tags))
+
+	if err := d.Set("tags", keyvaluetags.Ec2KeyValueTags(vpc.Tags).IgnoreAws().Map()); err != nil {
+		return fmt.Errorf("error setting tags: %s", err)
+	}
+
 	d.Set("owner_id", vpc.OwnerId)
 
 	arn := arn.ARN{