Pure Modifying field Values

[zhilong-xu]

What this PR does / why we need it:

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 #340 (6fbbfe7) into pure (d32286b) will decrease coverage by 0.03%.
The diff coverage is 68.51%.

@@            Coverage Diff             @@
##             pure     #340      +/-   ##
==========================================
- Coverage   70.65%   70.62%   -0.04%     
==========================================
  Files         166      166              
  Lines       16145    16163      +18     
  Branches     1992     2298     +306     
==========================================
+ Hits        11408    11415       +7     
- Misses       4057     4065       +8     
- Partials      680      683       +3     

Impacted Files	Coverage Δ
delfin/drivers/pure/flasharray/rest_handler.py	33.78% <25.00%> (-1.43%)	⬇️
delfin/drivers/pure/flasharray/pure_flasharray.py	82.82% <70.21%> (-2.38%)	⬇️
delfin/drivers/pure/flasharray/consts.py	100.00% <100.00%> (ø)