privilege: support FILE privilege in TiDB like MySQL

[cfzjywxk]

Feature Request

Is your feature request related to a problem? Please describe:

Describe the feature you'd like:

support FILE privilege in TiDB like MySQL, so users can control file related operations by users to reduce secure risks

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[morgo]

This has already been added for SELECT INTO OUTFILE in #19553

It is not applicable for the two remaining cases:

LOAD DATA does not support the local option:

mysql> LOAD DATA INFILE '/tmp/t.txt' INTO table test.t1;
ERROR 1105 (HY000): Load Data: don't support load data without local field

The function LOAD_FILE() has not been added, see #8436

mysql> SELECT LOAD_FILE('/tmp/t.txt');
ERROR 1305 (42000): FUNCTION load_file does not exist

As such, I am going to go ahead and close this issue.