Fix LB reconciliation to support multiple NSG

[shyamradhakrishnan]

What this PR does / why we need it:
Fix LB reconciliation to support multiple NSG

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 #259

[shyamradhakrishnan]

e2e test

[SynchronizedAfterSuite] PASSED [0.973 seconds]
[SynchronizedAfterSuite]
/home/ubuntu/go/src/github.com/oracle/cluster-api-provider-oci/test/e2e/e2e_suite_test.go:254

  Timeline >>
  STEP: Tearing down the management cluster @ 05/08/23 09:27:11.248
  << Timeline
------------------------------

Ran 6 of 25 Specs in 3721.669 seconds
SUCCESS! -- 6 Passed | 0 Failed | 0 Pending | 19 Skipped

[shyamradhakrishnan]

unit test

?   	github.com/oracle/cluster-api-provider-oci	[no test files]
ok  	github.com/oracle/cluster-api-provider-oci/api/v1beta1	40.936s	coverage: 24.1% of statements
ok  	github.com/oracle/cluster-api-provider-oci/api/v1beta2	0.037s	coverage: 15.8% of statements
?   	github.com/oracle/cluster-api-provider-oci/cloud/config	[no test files]
ok  	github.com/oracle/cluster-api-provider-oci/cloud/ociutil	0.007s	coverage: 19.6% of statements
ok  	github.com/oracle/cluster-api-provider-oci/cloud/scope	239.708s	coverage: 77.3% of statements
?   	github.com/oracle/cluster-api-provider-oci/cloud/scope/mocks	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/base	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/base/mock_base	[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/computemanagement	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/computemanagement/mock_computemanagement	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/containerengine	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/containerengine/mock_containerengine	[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/loadbalancer	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/cloud/services/loadbalancer/mock_lb	[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/cloud/util	0.027s	coverage: 55.8% of statements
ok  	github.com/oracle/cluster-api-provider-oci/controllers	25.996s	coverage: 67.5% of statements
ok  	github.com/oracle/cluster-api-provider-oci/exp/api/v1beta1	27.155s	coverage: 21.8% of statements
ok  	github.com/oracle/cluster-api-provider-oci/exp/api/v1beta2	0.022s	coverage: 10.9% of statements
ok  	github.com/oracle/cluster-api-provider-oci/exp/controllers	1.014s	coverage: 56.3% of statements
?   	github.com/oracle/cluster-api-provider-oci/feature	[no test files]
?   	github.com/oracle/cluster-api-provider-oci/version	[no test files]