[ISSUE-1018] Refine Storage Group Feature

[CraneShiEMC]

Purpose

Resolves #1018

Refine Storage Group Feature:

1. Add StorageGroupStatus
2. If we perform drive removal on the drive selected by some storagegroup with numberDrivesPerNode>0, the storagegroup's reconcilation should be triggered and it can select another drive if applicable.
3. Block StorageGroupSpec Update
4. Add StorageGroupController UT
5. For the drive with existing volumes that matches the driveSelector of some storage group, the drive should be selected into its matching storage group when its exsiting volumes removed.
6. The blocked storagegroup deletion can continue instantly after all exisitng volumes on drives of this storage group is removed.

PR checklist

• Add link to the issue
• Choose Project
• Choose PR label
• New unit tests added
• Modified code has meaningful comments
• All TODOs are linked with the issues
• All comments are resolved

Testing

Manual test passed.
Custom CI passed: https://asd-ecs-jenkins.isus.emc.com/job/csi-custom-ci/1559/
Custom Acceptance Passed: https://asd-ecs-jenkins.isus.emc.com/job/csi-custom-acceptance-tar_b_ona/36/

[codecov]

Codecov Report

Patch coverage: 77.01% and project coverage change: -0.20% ⚠️

Comparison is base (57095d3) 72.92% compared to head (b57da1f) 72.72%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1031      +/-   ##
==========================================
- Coverage   72.92%   72.72%   -0.20%     
==========================================
  Files          62       63       +1     
  Lines        8266     8796     +530     
==========================================
+ Hits         6028     6397     +369     
- Misses       1980     2111     +131     
- Partials      258      288      +30     

Flag	Coverage Δ
unittests	72.72% <77.01%> (-0.20%)	⬇️

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

Files Changed	Coverage Δ
...controllers/storagegroup/storagegroupcontroller.go	68.40% <75.32%> (ø)
pkg/crcontrollers/drive/drivecontroller.go	69.58% <90.00%> (+1.71%)	⬆️

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