[Enhancement] Optimization for string_search

[BiteTheDDDDt]

Proposed changes

Issue Number: close#7998

Problem Summary:

Describe the overview of changes.

Checklist(Required)

1. Does it affect the original behavior: (Yes/No/I Don't know)
2. Has unit tests been added: (Yes/No/No Need)
3. Has document been added or modified: (Yes/No/No Need)
4. Does it need to update dependencies: (Yes/No)
5. Are there any changes that cannot be rolled back: (Yes/No)

Further comments

If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...

[HappenLee]

LGTM

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[xiaokang]

@BiteTheDDDDt Should the following license comment for python be removed?

// This is taken from the python search string function doing string search (substring)
// using an optimized boyer-moore-horspool algorithm.
// http://hg.python.org/cpython/file/6b6c79eba944/Objects/stringlib/fastsearch.h

[BiteTheDDDDt]

@BiteTheDDDDt Should the following license comment for python be removed?

// This is taken from the python search string function doing string search (substring) // using an optimized boyer-moore-horspool algorithm. // http://hg.python.org/cpython/file/6b6c79eba944/Objects/stringlib/fastsearch.h

yes, and seems like should add apache license. Do you want add a pull request to fix it?