Add support for Cost Allocation

[Reinhard-Pilz-Dynatrace]

There exists customer demand for supporting management of cost centers and cost products.

We have a client who wants to know if there will be a terraform module to manager the allowlist for costcenter and costproduct CONTEXT They would like to use Dynatrace to do some configuration as code, but in the terraform registry https://registry.terraform.io/providers/dynatrace-oss/dynatrace/latest/docs there is no way to configure costcenter and costproduct for our instances.

https://docs.dynatrace.com/docs/discover-dynatrace/references/dynatrace-api/account-management-api/dynatrace-platform-subscription-api/cost-allocation