[fix](agg) reset the content of grouping exprs instead of replace it with original exprs

[starocean999]

Proposed changes

Issue Number: close #xxx

Problem summary

after expr rewrite, the sql will be re-analyzed. The reset method is called before re-analyze. The GroupByClause's reset method is not correct, this pr fix it.

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 (If Yes, please explain WHY)
   • 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...

[dataalive]

close #13350

[hello-stephen]

https://doris-community-test-1308700295.cos.ap-hongkong.myqcloud.com/tmp/20221014224602_clickbench_pr_29626.html

[yiguolei]

LGTM