testsys: shorten default namespace and CRD API group

[etungsten]

Issue number:
Resolves #628

Description of changes:

    testsys: shorten default namespace to 'testsys'
    
    This shortens TestSys default namespace from 'testsys-bottlerocket-aws'
    to 'testsys'

    testsys: change CRD API group to 'testsys.system'
    
    This changes the TestSys CRD API group from 'testsys.bottlerocket.aws'
    to 'testsys.system'. This makes it less specific to Bottlerocket when
    TestSys can be used to test other OSes in any K8s cluster.

Testing done:
All testsys images built fine, testsys CLI installs fine.

Deployed testsys to K8s cluster, testsys api-resources are created in the testsys namespace as expected.
TestSys CRD group/APIVersion is as expected:

$ kubectl api-resources 
...
resources                                      testsys.system/v1                      true         Resource
tests                                          testsys.system/v1                      true         Test


$ kubectl get pods -A
NAMESPACE     NAME                                  READY   STATUS    RESTARTS   AGE
...
testsys       testsys-controller-5595cc7b94-g8npd   1/1     Running   0          60s


$ kubectl get crds
NAME                                         CREATED AT
eniconfigs.crd.k8s.amazonaws.com             2022-08-10T21:55:07Z
resources.testsys.system                     2022-10-31T19:38:35Z
securitygrouppolicies.vpcresources.k8s.aws   2022-08-10T21:55:10Z
tests.testsys.system                         2022-10-31T19:38:35Z

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[stmcginnis]

We shouldn't use a legitimate domain name like testsys.com.

[stmcginnis]

Looks good!