Fix fill the string field twice when string index exists

[yah01]

Signed-off-by: yah01 yang.cen@zilliz.com
related #20765
For scalar index, we have retrieved the field data from index, re-fill would cause much performance downgrade

[yah01]

Also the filling is not efficient for string type, as it needs to read and deserialize the same binlog many times

[codecov]

Codecov Report

Merging #21852 (a8d8403) into master (09124f8) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master   #21852      +/-   ##
==========================================
+ Coverage   82.36%   82.39%   +0.03%     
==========================================
  Files         694      694              
  Lines       93577    93578       +1     
==========================================
+ Hits        77074    77108      +34     
+ Misses      13640    13610      -30     
+ Partials     2863     2860       -3     

Impacted Files	Coverage Δ
internal/querynode/segment.go	81.65% <100.00%> (+0.02%)	⬆️
internal/querycoordv2/job/scheduler.go	88.42% <0.00%> (-6.32%)	⬇️
internal/datacoord/session_manager.go	83.24% <0.00%> (-2.54%)	⬇️
internal/mq/msgstream/mq_msgstream.go	77.66% <0.00%> (-1.81%)	⬇️
internal/querycoordv2/checkers/segment_checker.go	85.41% <0.00%> (-1.57%)	⬇️
internal/distributed/querycoord/client/client.go	79.09% <0.00%> (-1.40%)	⬇️
internal/proxy/meta_cache.go	86.65% <0.00%> (-0.94%)	⬇️
internal/rootcoord/quota_center.go	85.59% <0.00%> (-0.64%)	⬇️
internal/proxy/impl.go	88.96% <0.00%> (+0.32%)	⬆️
internal/indexnode/task.go	50.92% <0.00%> (+0.53%)	⬆️
... and 9 more

[yah01]

/run-cpu-e2e

[congqixia]

/kind improvement

[congqixia]

/lgtm

[sre-ci-robot]

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