Removes get_account_read_entry_with_lock()

[brooksprumo]

Problem

See #34786 for background.

We want to limit the use of ReadAccountMapEntry, from AccountsIndex, everywhere. Ultimately removing it once there are no more uses.

We want to remove get_account_read_entry_with_lock(), and it is only used by get_account_read_entry(), so the separate function can be removed.

Summary of Changes

Removes get_account_read_entry_with_lock() and inlines the impl into get_account_read_entry()

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (d87e7bc) 81.6% compared to head (c8b430a) 81.6%.
Report is 11 commits behind head on master.

❗ Current head c8b430a differs from pull request most recent head 811b986. Consider uploading reports for the commit 811b986 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #35240   +/-   ##
=======================================
  Coverage    81.6%    81.6%           
=======================================
  Files         833      833           
  Lines      224768   224760    -8     
=======================================
+ Hits       183475   183489   +14     
+ Misses      41293    41271   -22     

[HaoranYi]

Nice!