Split update_index function into two

[roryharr]

Problem

Update Index is used for both cached accounts and uncached accounts which leads to unnecessary data structure allocations (reclaims). This is also a building block towards ephemeral accounts skipping index updates

Summary of Changes

• Created a new function refactor_update_index_cached

Fixes #

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.5%. Comparing base (552674f) to head (259ac21).
⚠️ Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##           master    #9963     +/-   ##
=========================================
- Coverage    82.5%    82.5%   -0.1%     
=========================================
  Files         844      844             
  Lines      316472   316510     +38     
=========================================
+ Hits       261309   261335     +26     
- Misses      55163    55175     +12     

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[brooksprumo]

Looks good