test(mtr): add some mtr test cases(#497)

[davidshiz]

[summary]
add test cases about unsigned/escape/replace into/zerofill

Summary about this PR

Issue Number: ref #497

Tests Check List

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Changelog

• New Feature
• Bug Fix
• Performance Improvement
• Build/Testing/CI/CD
• Documentation
• Not for changelog (changelog entry is not required)

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features

[mergify]

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[codecov]

Codecov Report

Base: 43.30% // Head: 43.32% // Increases project coverage by +0.02% 🎉

Coverage data is based on head (682944f) compared to base (74160c0).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@                 Coverage Diff                 @@
##           stonedb-5.7-dev    #1195      +/-   ##
===================================================
+ Coverage            43.30%   43.32%   +0.02%     
===================================================
  Files                 1830     1830              
  Lines               396111   396111              
===================================================
+ Hits                171535   171620      +85     
+ Misses              224576   224491      -85     

Impacted Files	Coverage Δ
storage/tianmu/core/engine_convert.cpp	68.23% <100.00%> (ø)
storage/innobase/include/ut0mutex.ic	52.38% <0.00%> (-19.05%)	⬇️
strings/str2int.c	72.72% <0.00%> (-6.07%)	⬇️
sql/mdl.cc	66.11% <0.00%> (-3.33%)	⬇️
storage/innobase/buf/buf0buddy.cc	33.76% <0.00%> (-2.60%)	⬇️
storage/myisam/mi_search.c	38.65% <0.00%> (-1.69%)	⬇️
storage/myisam/mi_delete.c	25.52% <0.00%> (-1.21%)	⬇️
storage/innobase/rem/rem0rec.cc	68.08% <0.00%> (-1.02%)	⬇️
storage/innobase/btr/btr0bulk.cc	80.89% <0.00%> (-0.96%)	⬇️
sql/conn_handler/connection_handler_manager.cc	44.44% <0.00%> (-0.86%)	⬇️
... and 46 more

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[shangyanwen]

LGMT

[lujiashun]

LGTM