[Enhancement]: delete oracle code in errno.def

[hnwyllmm]

Enhancement
There're too many oracle related code in errno files.
The related files may include (src/share):

• gen_errno.pl. generating cpp files depends on ob_errno.def
• ob_errno.def. defining error code.
• ob_errno.h, ob_errno.cpp. Generated by gen_errno.pl

We can delete oracle related code in gen_errno.pl and then ob_errno.def.
Please feel free to create more issues if you need.

[NTLx]

I would like to work on this issue.

Plan:

1. Analyze the scope of Oracle-related code in gen_errno.pl and ob_errno.def
2. Remove Oracle-specific macro handlers from gen_errno.pl
3. Remove DEFINE_ORACLE_ERROR* and DEFINE_PLS_ERROR* definitions from ob_errno.def
4. Regenerate ob_errno.h and ob_errno.cpp
5. Verify build success and no remaining Oracle references

Question: Given the large number of Oracle error definitions (~1060 lines), should I:

• (A) Remove all Oracle-related definitions in one PR, or
• (B) Split into multiple smaller PRs (e.g., by error code range)?

I will submit a PR within 48 hours after receiving guidance.