[fix](planner)fix 'char' function's toSql implementation is wrong

[starocean999]

Proposed changes

create view vv1 as select char(k2) from t2;

The create view sql should be:

CREATE VIEW vv1 COMMENT 'VIEW' AS SELECT char(k2 using utf8) AS char(``k2`` using utf8) FROM default_cluster:tt.t2;

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...

[starocean999]

run buildall

[morrySnow]

i think we should use substr() to remove the first and the last character. replace will generate wrong sql, think about 'ab\'c'

[starocean999]

run buildall

[doris-robot]

(From new machine)TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 48.42 seconds
stream load tsv: 529 seconds loaded 74807831229 Bytes, about 134 MB/s
stream load json: 21 seconds loaded 2358488459 Bytes, about 107 MB/s
stream load orc: 64 seconds loaded 1101869774 Bytes, about 16 MB/s
stream load parquet: 31 seconds loaded 861443392 Bytes, about 26 MB/s
insert into select: 29.0 seconds inserted 10000000 Rows, about 344K ops/s
storage size: 17162002195 Bytes

[xiaokang]

LGTM

[github-actions]

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

[github-actions]

PR approved by anyone and no changes requested.