expression: make regex binary and rlike binary be case sensitive

[lysu]

What problem does this PR solve?

In current TiDB, regexp binary is case insensitive.

mysql> select 'a' regexp 'A', 'a' regexp binary 'A';
+----------------+-----------------------+
| 'a' regexp 'A' | 'a' regexp binary 'A' |
+----------------+-----------------------+
|              1 |                     1 |
+----------------+-----------------------+

but MySQL is case sensitive:

mysql> select 'a' regexp 'A', 'a' regexp binary 'A';
+----------------+-----------------------+
| 'a' regexp 'A' | 'a' regexp binary 'A' |
+----------------+-----------------------+
|              1 |                     0 |
+----------------+-----------------------+

What is changed and how it works?

not only check the first argument('a') but also the second argument(binary 'A') to decide whether using builtinRegexpBinarySig

Check List

Tests

• Unit test
• Integration test

Code changes

• impl

Side effects

• N/A

Related changes

• Need to cherry-pick to the release branch

---

This change is 

[lysu]

/run-all-tests

[zz-jason]

LGTM

[codecov]

Codecov Report

Merging #11502 into master will decrease coverage by 0.0241%.
The diff coverage is 100%.

@@               Coverage Diff                @@
##             master     #11502        +/-   ##
================================================
- Coverage   81.3774%   81.3532%   -0.0242%     
================================================
  Files           424        424                
  Lines         90922      90922                
================================================
- Hits          73990      73968        -22     
- Misses        11619      11632        +13     
- Partials       5313       5322         +9

[codecov]

Codecov Report

Merging #11502 into master will decrease coverage by 0.0241%.
The diff coverage is 100%.

@@               Coverage Diff                @@
##             master     #11502        +/-   ##
================================================
- Coverage   81.3774%   81.3532%   -0.0242%     
================================================
  Files           424        424                
  Lines         90922      90922                
================================================
- Hits          73990      73968        -22     
- Misses        11619      11632        +13     
- Partials       5313       5322         +9

[qw4990]

LGTM

[sre-bot]

cherry pick to release-3.0 in PR #11504

[sre-bot]

cherry pick to release-2.1 in PR #11505