[Bug]: The extractvalue function in ob for mysql is not compatible with the native MySQL function

[PanternBao]

Describe the bug

extractvalue in ob for mysql mode can't support xpath array index

Environment

• OS Version and CPU Arch(uname -a):

• OB Version(LD_LIBRARY_PATH=../lib:$LD_LIBRARY_PATH ./observer -V):
  release v4.2.2.0, and from issue: [Bug]: The extractvalue function in ob for mysql is not compatible with the native MySQL function #1851

Fast Reproduce Steps(Required)

Steps to reproduce the behavior:

Expected behavior

like mysql8:

Actual Behavior

Additional context

[hnwyllmm]

Thanks for your report but we will fix this issue in a few months.