Implements EC2 Volume

[haarchri]

Description of your changes

add ec2/volume

Fixes #739

I have:

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

How has this code been tested

➜  provider-aws git:(ebs-volume) ✗ kubectl apply -f examples/ec2/volume.yaml            
volume.ec2.aws.crossplane.io/example created

➜  provider-aws git:(ebs-volume) ✗ kubectl describe volume.ec2.aws.crossplane.io/example
Name:         example
Namespace:    
Labels:       <none>
Annotations:  crossplane.io/external-name: vol-0cc9d21d80a60ec2a
API Version:  ec2.aws.crossplane.io/v1alpha1
Kind:         Volume
Metadata:
  Creation Timestamp:  2021-07-19T10:13:54Z
  Finalizers:
    finalizer.managedresource.crossplane.io
  Generation:        2
  Resource Version:  1563377
  Self Link:         /apis/ec2.aws.crossplane.io/v1alpha1/volumes/example
  UID:               61172836-e203-49d7-a755-6b2677f5d7d0
Spec:
  Deletion Policy:  Delete
  For Provider:
    Availability Zone:  eu-central-1a
    Encrypted:          true
    Kms Key ID:         ea87e120-8417-4ade-8499-9e093d5664d7
    Kms Key ID Ref:
      Name:       dev-key
    Region:       eu-central-1
    Size:         1
    Volume Type:  gp3
  Provider Config Ref:
    Name:  default
Status:
  At Provider:
    Create Time:  2021-07-19T10:13:55Z
    State:        available
    Volume ID:    vol-0cc9d21d80a60ec2a
  Conditions:
    Last Transition Time:  2021-07-19T10:13:55Z
    Reason:                ReconcileSuccess
    Status:                True
    Type:                  Synced
    Last Transition Time:  2021-07-19T10:14:56Z
    Reason:                Available
    Status:                True
    Type:                  Ready
Events:
  Type    Reason                   Age   From                                  Message
  ----    ------                   ----  ----                                  -------
  Normal  CreatedExternalResource  2m4s  managed/volume.ec2.aws.crossplane.io  Successfully requested creation of external resource

➜  provider-aws git:(ebs-volume) ✗ kubectl delete -f examples/ec2/volume.yaml           
volume.ec2.aws.crossplane.io "example" deleted

[AaronME]

@haarchri Please rebase this and we can run through testing.

Thank you!

[haarchri]

still blocked by #920

[haarchri]

@AaronME thanks for bump codeGenerator with #920 i rebased and tested this PR again

 kubectl get volume
NAME      READY   SYNCED   EXTERNAL-NAME
example   True    True     vol-0b94a54f369e2d42e

[AaronME]

LGTM! Thank you @haarchri !