Add CM support for VMAX Driver

[joseph-v]

What this PR does / why we need it:
Add CM support for VMAX Driver

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

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Merging #900 (e0e621f) into master (7953bc8) will increase coverage by 0.02%.
The diff coverage is 71.69%.

@@            Coverage Diff             @@
##           master     #900      +/-   ##
==========================================
+ Coverage   71.31%   71.34%   +0.02%     
==========================================
  Files         182      182              
  Lines       21237    21240       +3     
  Branches     3243     3241       -2     
==========================================
+ Hits        15146    15153       +7     
+ Misses       5064     5060       -4     
  Partials     1027     1027              

Impacted Files	Coverage Δ
...drivers/dell_emc/vmax/alert_handler/snmp_alerts.py	90.47% <50.00%> (-2.03%)	⬇️
delfin/drivers/dell_emc/vmax/client.py	81.72% <64.51%> (+2.08%)	⬆️
delfin/drivers/dell_emc/vmax/vmax.py	83.33% <85.00%> (ø)
delfin/drivers/fake_storage/__init__.py	93.63% <0.00%> (-0.77%)	⬇️

[wisererik]

LGTM

[skdwriting]

LGTM