Allow for importing confluent_api_key using terraform import resources

[tarciosaraiva]

Hi there,
terraform has been supporting import blocks since v1.5 and although marked as experimental it is a nice addition to their configuration language as it reduces the amount of cli commands required.

Having a dependency on an environment variable limits the import options. The use case I have in mind is using a data block to read the secret from a secret store and populate the key appropriately in the imported resource.

Any chance this could be looked into?

Original request on this issue 👉🏻 #375 (comment)