Move to CLI schema

[ezgidemirel]

Description of your changes

This change updates the provider to use CLI schema. This change is on top of this PR.

Fixes #166

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Created/deleted KMS, Neptune Cluster and Neptune Instance resources.

NAME                                     READY   SYNCED   EXTERNAL-NAME                          AGE
key.kms.aws.jet.crossplane.io/ezgi-key   True    True     46964507-81f5-4b23-9bc2-15dc87a2c1b1   15m

NAME                                                          READY   SYNCED   EXTERNAL-NAME   AGE
clusterinstance.neptune.aws.jet.crossplane.io/ezgi-instance   True    True     ezgi-instance   10m

NAME                                                 READY   SYNCED   EXTERNAL-NAME   AGE
cluster.neptune.aws.jet.crossplane.io/ezgi-cluster   True    True     ezgi-cluster    13m