fix: convert memory by quantity.Value in overcommit controller

[WangZzzhe]

What type of PR is this?

Bug fixes

What this PR does / why we need it:

Memory value overflow when node patch a large memory allocatable in status, eg. '1Ei'.
Convert memory value by quantity.Value which can cover larger values than MilliValue.

Which issue(s) this PR fixes:

Special notes for your reviewer:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 56.16%. Comparing base (74b648c) to head (6dbc70d).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #588      +/-   ##
==========================================
+ Coverage   56.06%   56.16%   +0.10%     
==========================================
  Files         534      535       +1     
  Lines       49807    49831      +24     
==========================================
+ Hits        27924    27988      +64     
+ Misses      18325    18292      -33     
+ Partials     3558     3551       -7     

Flag	Coverage Δ
unittest	56.16% <100.00%> (+0.10%)	⬆️

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