fix: refactor the service clients

[joekr]

We want to be more consistent with naming
https://go.dev/blog/package-names

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

[joekr]

unit tests

?       github.com/oracle/cluster-api-provider-oci      [no test files]
?       github.com/oracle/cluster-api-provider-oci/api/v1beta1  [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/config [no test files]
ok      github.com/oracle/cluster-api-provider-oci/cloud/ociutil        0.481s  coverage: 30.3% of statements
ok      github.com/oracle/cluster-api-provider-oci/cloud/scope  75.401s coverage: 83.5% of statements
?       github.com/oracle/cluster-api-provider-oci/cloud/scope/mocks    [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/compute       [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/compute/mock_compute  [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/identity      [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/identity/mock_identity        [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/networkloadbalancer   [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/networkloadbalancer/mock_nlb  [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/vcn   [no test files]
?       github.com/oracle/cluster-api-provider-oci/cloud/services/vcn/mock_vcn  [no test files]
ok      github.com/oracle/cluster-api-provider-oci/controllers  25.852s coverage: 68.3% of statements

e2e tests