Added lifecycle to ignore null changes

[Mitrofanov]

what
Fix for issues with cluster config edit (terraform always wants to change provisioned_throughput config as follows)

why
~ resource "aws_msk_cluster" "default" {
id = "arn:aws:kafka:eu-central-1:0000000:cluster/kafka/"
# (12 unchanged attributes hidden)

  ~ broker_node_group_info {
        # (4 unchanged attributes hidden)

      ~ storage_info {
          ~ ebs_storage_info {
                # (1 unchanged attribute hidden)

              - provisioned_throughput {
                  - enabled           = false -> null
                  - volume_throughput = 0 -> null
                }
            }
        }

      # (1 unchanged block hidden)
  }

  # (5 unchanged blocks hidden)

}
This leads to following error:

Error: updating MSK Cluster (arn:aws:kafka:eu-central-1:00000:cluster/kafka/) security: BadRequestException: The request does not include any updates to the security setting of the cluster. Verify the request, then try again.
│ {
│ RespMetadata: {
│ StatusCode: 400,
│ RequestID: "1d43c33f-6f0e-4ad7-b25f-17130137ccd2"
│ },
│ Message_: "BadRequestException: The request does not include any updates to the EBS volumes of the cluster. Verify the request, then try again."
│ }