[fix](csv reader) fix wrong result when escape same as enclose

[sollhui]

What problem does this PR solve?

Fix wrong result when escape same as enclose, introduced by #50101

data:

50,"{""a"": 1}"
60,"{""a"": 2}"

query

select * from local( "backend_id" = "1760087225568", "file_path" = "test.csv", "format" = "csv", "column_separator" = ",", "enclose" = "\"", "escape" = "\""

expectation：

+------+------------+
| k1   | k2         |
+------+------------+
|   50 | {"a": 1} |
|   60 | {"a": 2} |
+------+------------+

real:

+------+------------------------+
| k1   | k2                     |
+------+------------------------+
|   50 | {"a": 1}
60,{"a": 2}

 |
+------+------------------------+

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

Thank you for your contribution to Apache Doris.
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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[sollhui]

run buildall

[morningman]

LGTM

[github-actions]

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

[github-actions]

PR approved by anyone and no changes requested.

[doris-robot]

ClickBench: Total hot run time: 28.9 s

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/clickbench-tools
ClickBench test result on commit 546bbcc3a9ca221b8ad4afe4b885afad5a897138, data reload: false

query1	0.06	0.05	0.05
query2	0.10	0.06	0.05
query3	0.26	0.10	0.09
query4	1.60	0.12	0.12
query5	0.28	0.27	0.27
query6	1.20	0.67	0.67
query7	0.04	0.02	0.02
query8	0.06	0.04	0.04
query9	0.65	0.56	0.56
query10	0.61	0.62	0.63
query11	0.20	0.13	0.13
query12	0.17	0.14	0.13
query13	0.63	0.61	0.63
query14	1.03	1.03	1.03
query15	0.90	0.86	0.90
query16	0.41	0.41	0.42
query17	1.15	1.14	1.23
query18	0.25	0.23	0.22
query19	2.04	1.97	1.90
query20	0.02	0.02	0.01
query21	15.36	0.20	0.14
query22	5.10	0.08	0.05
query23	15.62	0.32	0.12
query24	3.04	0.78	0.43
query25	0.08	0.06	0.07
query26	0.16	0.15	0.16
query27	0.08	0.06	0.07
query28	4.39	1.17	0.97
query29	12.63	4.50	3.71
query30	0.30	0.15	0.12
query31	2.84	0.67	0.40
query32	3.26	0.58	0.48
query33	3.09	3.16	3.18
query34	15.91	5.28	4.59
query35	4.60	4.62	4.63
query36	0.71	0.55	0.52
query37	0.11	0.07	0.07
query38	0.07	0.04	0.04
query39	0.04	0.03	0.04
query40	0.18	0.15	0.15
query41	0.09	0.03	0.04
query42	0.04	0.03	0.04
query43	0.05	0.04	0.04
Total cold run time: 99.41 s
Total hot run time: 28.9 s

[doris-robot]

BE UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	52.70% (18049/34249)
Line Coverage	37.99% (164078/431857)
Region Coverage	32.34% (125106/386896)
Branch Coverage	33.74% (54725/162188)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	71.45% (24055/33668)
Line Coverage	57.84% (250216/432602)
Region Coverage	52.90% (207609/392492)
Branch Coverage	54.64% (89227/163297)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	71.44% (24054/33668)
Line Coverage	57.84% (250230/432602)
Region Coverage	52.91% (207662/392492)
Branch Coverage	54.65% (89240/163297)

[liaoxin01]

LGTM