[refractor](schema) refractor function Schema::get_column_by_field to make it simple

[cambyzju]

Proposed changes

Issue Number: close #xxx

Problem summary

DataTypeFactory::instance().create_data_type will consider Field.is_nullable, may return type T or Nullable(T).
Then datatype create_column, will create Column or ColumnNullable(Column).

So we do not need to create ColumnNullable manually.

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...

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[hello-stephen]

TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 35.51 seconds
load time: 500 seconds
storage size: 17122462582 Bytes
https://doris-community-test-1308700295.cos.ap-hongkong.myqcloud.com/tmp/20230117182551_clickbench_pr_82539.html

[yinzhijian]

LGTM

[github-actions]

PR approved by anyone and no changes requested.