r/vpn_connection_route: Wait until route is available/deleted

[radeksimko]

The lack of waiters may cause some confusions and handing over resource when it's actually ready is a convention anyway.

Test results

TF_ACC=1 go test ./aws -v -run=TestAccAWSVpnConnectionRoute_ -timeout 120m
=== RUN   TestAccAWSVpnConnectionRoute_basic
--- PASS: TestAccAWSVpnConnectionRoute_basic (247.11s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	247.156s

[catsby]

👍

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!