[Function](vec) use const column to opt function current_time()

[HappenLee]

Proposed changes

Before：

mysql> select count(current_time()) from hits;
+-----------------------+
| count(current_time()) |
+-----------------------+
| 99997497 |
+-----------------------+
1 row in set (0.52 sec)

After:

mysql> select count(current_time()) from hits;
+-----------------------+
| count(current_time()) |
+-----------------------+
| 99997497 |
+-----------------------+
1 row in set (0.36 sec)

Problem summary

Describe your changes.

Checklist(Required)

• Does it affect the original behavior
• Has unit tests been added
• Has document been added or modified
• Does it need to update dependencies
• Is this PR support rollback (If NO, please explain WHY)

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! 👍"

[github-actions]

PR approved by anyone and no changes requested.

[github-actions]

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

[hello-stephen]

TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 35 seconds
stream load tsv: 468 seconds loaded 74807831229 Bytes, about 152 MB/s
stream load json: 38 seconds loaded 2358488459 Bytes, about 59 MB/s
stream load orc: 67 seconds loaded 1101869774 Bytes, about 15 MB/s
stream load parquet: 28 seconds loaded 861443392 Bytes, about 29 MB/s
https://doris-community-test-1308700295.cos.ap-hongkong.myqcloud.com/tmp/20230220154003_clickbench_pr_100436.html

[HappenLee]

run buildall

[HappenLee]

run buildall

[BiteTheDDDDt]

LGTM

[github-actions]

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