fix: delete unused functions AppendXXX

[WUBBBB]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

delete unused functions

• What is the current behavior? (You can also link to an open issue here)

• What is the new behavior (if this is a feature change)?

[codecov]

Codecov Report

Merging #2062 (21068e6) into main (3cc6a64) will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##               main    #2062      +/-   ##
============================================
+ Coverage     75.67%   75.68%   +0.01%     
  Complexity      347      347              
============================================
  Files           615      615              
  Lines        116901   116901              
  Branches       1015     1015              
============================================
+ Hits          88463    88482      +19     
+ Misses        28229    28210      -19     
  Partials        209      209              

Impacted Files	Coverage Δ
src/codec/codec.h	100.00% <ø> (ø)
src/rpc/rpc_client.h	83.78% <0.00%> (-5.41%)	⬇️
src/catalog/tablet_catalog.cc	69.97% <0.00%> (-0.81%)	⬇️
hybridse/src/codec/fe_row_codec.cc	78.33% <0.00%> (-0.63%)	⬇️
src/client/tablet_client.cc	55.03% <0.00%> (-0.34%)	⬇️
src/client/ns_client.cc	46.65% <0.00%> (-0.30%)	⬇️
src/catalog/client_manager.cc	42.20% <0.00%> (-0.29%)	⬇️
src/sdk/sql_cluster_router.cc	54.92% <0.00%> (-0.13%)	⬇️
src/nameserver/name_server_impl.cc	42.63% <0.00%> (-0.02%)	⬇️
hybridse/src/vm/runner.cc	67.77% <0.00%> (ø)
... and 7 more

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[github-actions]

SDK Test Report

  75 files    75 suites   5m 30s ⏱️
163 tests 161 ✔️ 2 💤 0 ❌
204 runs  202 ✔️ 2 💤 0 ❌

Results for commit 21068e6.

[github-actions]

Linux Test Report

       54 files       196 suites   51m 36s ⏱️
  9 008 tests   9 004 ✔️ 4 💤 0 ❌
13 259 runs  13 255 ✔️ 4 💤 0 ❌

Results for commit 21068e6.