[BugFix] Fix files csv invisible character separator

[wyb]

Why I'm doing:

when files() gets csv schema, invisible character separator is not converted, resulting in incorrect schema.

What I'm doing:

Fixes #issue

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.3
  • 3.2
  • 3.1
  • 3.0
  • 2.5

Documentation PRs only:

If you are submitting a PR that adds or changes English documentation and have not
included Chinese documentation, then you can check the box to request GPT to translate the
English doc to Chinese. Please ensure to uncheck the Do not translate box if translation is needed.
The workflow will generate a new PR with the Chinese translation after this PR is merged.

• Yes, translate English markdown files with GPT
• Do not translate

[sonarcloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

[Java-Extensions Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[BE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 2 / 2 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	com/starrocks/catalog/TableFunctionTable.java	2	2	100.00%	[]

[github-actions]

@Mergifyio backport branch-3.3

[mergify]

backport branch-3.3

✅ Backports have been created

• #49727 [BugFix] Fix files csv invisible character separator (backport #49718) has been created for branch branch-3.3