Fix missing dataset config in arrowflight when using a named collection

[alex-shchetkov]

When using a named collection with the arrowFlight table function or table engine, clickhouse ignores the dataset config, and ends up passing and empty string to the flight enabled server.
IE

CREATE NAMED COLLECTION named_coll AS
host = '0.0.0.0' OVERRIDABLE;

select
  *
from
  arrowflight(
    named_coll,
    host = '0.0.0.0',
    port = 5005,
    use_basic_authentication = False,
    dataset = 'my_dataset'
  )

The above sends dataset='' to that host.

Changelog category (leave one):

• Bug Fix (user-visible misbehavior in an official stable release)

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

ArrowFlight endpoint sources that required an SSL connection (such as behind an AWS ALB) can now properly request a specific dataset.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

[CLAassistant]

All committers have signed the CLA.

[clickhouse-gh]

Workflow [PR], commit [099f273]

Summary: ❌

job_name	test_name	status	info	comment
Stateless tests (amd_ubsan, parallel)		failure
	00900_long_parquet_load	FAIL	cidb, flaky
Stateless tests (amd_tsan, s3 storage, parallel)		failure
	01201_read_single_thread_in_order	FAIL	cidb, flaky

[alex-shchetkov]

There was an issue with gh cli failing to add a label. (cli/cli#11986)

[2025-10-21 23:01:05] > Start execution for [python3 ./ci/jobs/scripts/workflow_hooks/pr_description.py]
[2025-10-21 23:01:05] Run command: [python3 ./ci/jobs/scripts/workflow_hooks/pr_description.py]
[2025-10-21 23:01:05] 
[2025-10-21 23:01:05] Add labels [['pr-bugfix']]
[2025-10-21 23:01:05] Run command: [gh pr edit 88868 --add-label 'pr-bugfix']
[2025-10-21 23:01:05] GraphQL: Projects (classic) is being deprecated in favor of the new Projects experience, see: [https://github.blog/changelog/2024-05-23-sunset-notice-projects-classic/.](https://github.blog/changelog/2024-05-23-sunset-notice-projects-classic/) (repository.pullRequest.projectCards)
[2025-10-21 23:01:05] ERROR: command failed, exit code: 1, retry: 1/1

It somehow only affected my previous ci run, and seems to be working for other PRs submitted after mine.
I merged master to re-trigger the ci run.

[alexey-milovidov]

The change LGTM