adding support and validation for providing FQDN

[aggarwalta]

What type of PR is this?

/kind enhancement

What this PR does / why we need it:
This PR brings in additional support and validation for providing FQDN instead of IP address.

Which issue(s) this PR fixes:

Fixes #133

Test Report Added?:
/kind TESTED

Test Report:
1. Test Results for Live k8s cluster

Tested with CSI version 2.3.0

bin/vdoctl deploy --spec https://github.com/vmware-tanzu/vsphere-kubernetes-drivers-operator/releases/download/0.1.1/vdo-spec-vanilla-k8s.yaml
Tip: now that you have deployed VDO, you might want to try 'vdoctl configure drivers' to configure vsphere drivers

bin/vdoctl configure drivers
Do you want to configure CloudProvider? (Y/N) y
Please provide the vcenter IP/FQDN for configuring CloudProvider 
VC IP/FQDN sc2-10-187-159-221.nimbus.eng.vmware.com
Do you want to establish a secure connection? (Y/N) n
Please provide the credentials for configuring CloudProvider
Username administrator@vsphere.local
Password ********
Datacenter(s) Datacenter

kubectl get pods -A
kube-system         vsphere-cloud-controller-manager-nmr7n    1/1     Running   0          16s
vmware-system-csi   vsphere-csi-controller-8489c5b7f8-gm7p8   6/6     Running   0          13s
vmware-system-csi   vsphere-csi-node-69wsn                    3/3     Running   0          13s
vmware-system-csi   vsphere-csi-node-k2wlj                    3/3     Running   0          13s
vmware-system-vdo   vdo-controller-manager-5d749b8fc4-2n6pr   2/2     Running   0          11m

bin/vdoctl status
CloudProvider   : Configured
         vCenter : 
                sc2-10-187-159-221.nimbus.eng.vmware.com  (Credentials Verified)
         Nodes : 
                 master-vm : ready 
                 worker-vm : ready 
StorageProvider : Deployed
         vCenter : 
                sc2-10-187-159-221.nimbus.eng.vmware.com  (Credentials Verified)

2. Test Results for KIND cluster

Tested with CSI version 2.3.0

bin/vdoctl configure drivers
Do you want to configure CloudProvider? (Y/N) y
Please provide the vcenter IP/FQDN for configuring CloudProvider 
VC IP/FQDN sc2-10-185-38-193.eng.vmware.com
Do you want to establish a secure connection? (Y/N) n
Please provide the credentials for configuring CloudProvider
Username administrator@vsphere.local
Password ********
Datacenter(s) Datacenter

kubectl get pods -A
NAMESPACE            NAME                                         READY   STATUS    RESTARTS   AGE
kube-system          vsphere-cloud-controller-manager-l57qh       1/1     Running   0          117m
vmware-system-csi    vsphere-csi-controller-8489c5b7f8-k2pzg      6/6     Running   0          112m
vmware-system-csi    vsphere-csi-node-98gc6                       3/3     Running   0          112m
vmware-system-vdo    vdo-controller-manager-7f98f4856d-f6v6p      2/2     Running   1          28h

bin/vdoctl status                                                                        
CloudProvider   : Configured
         vCenter : 
                sc2-10-185-38-193.eng.vmware.com  (Credentials Verified)
         Nodes : 
                 kind-control-plane : ready 
StorageProvider : Deployed
         vCenter : 
                sc2-10-185-38-193.eng.vmware.com  (Credentials Verified)

Special notes for your reviewer:

[codecov-commenter]

Codecov Report

Merging #137 (ed16cc3) into main (718213e) will decrease coverage by 0.10%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #137      +/-   ##
==========================================
- Coverage   52.22%   52.12%   -0.11%     
==========================================
  Files           6        6              
  Lines        1480     1508      +28     
==========================================
+ Hits          773      786      +13     
- Misses        610      623      +13     
- Partials       97       99       +2     

Flag	Coverage Δ
unittests	52.12% <ø> (-0.11%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
controllers/vdoconfig_controller.go	47.35% <0.00%> (-0.03%)	⬇️

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[asifdxtreme]

LGTM

[asifdxtreme]

@aggarwalta Please rebase