Add support for Synthetic Test

[bkalcho]

What problem are you facing?

I do not see that latest version of provider supports management of Synthetic Tests?

How could Upbound help solve your problem?

It would be nice to implement such feature, especially as it is already supported in the Terraform DataDog provider used to generate XP provider code. In terraform you can perform configuration via datadog_synthetics_test resource.

Epic #

[khalilj-appsflyer]

+1

[khalilj]

I have fixed this issue. Preparing a PR.