test: add acceptance tests for the import of an endpoint

[lriberon]

Description

The terraform import command has been tested with an existing endpoint resource and the Acceptation test has been created for it.

How to test?

1. Perform a curl request to fetch the list of existing endpoints of your account
2. Go to the examples directory
3. Run the terraform init command
4. Run the import command with one of the IDs of your existing endpoints: terraform import datadome_endpoint.new_endpoint [REPLACE_BY_YOUR_ID]. You should see the Import successful! output.
5. Run the terraform show command to verify that the endpoint has been correctly imported.