Antalya 25.8 Backport of #89914: Show datalake catalogs in SHOW DATABASES query

[zvonand]

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 to CHANGELOG.md):

Now ClickHouse will show data lake catalog database in SHOW DATABASES query by default (ClickHouse#89914 by @alesapin)

CI/CD Options

Exclude tests:

• Fast test
• Integration Tests
• Stateless tests
• Stateful tests
• Performance tests
• All with ASAN
• All with TSAN
• All with MSAN
• All with UBSAN
• All with Coverage
• All with Aarch64
• All Regression
• Disable CI Cache

Regression jobs to run:

• Fast suites (mostly <1h)
• Aggregate Functions (2h)
• Alter (1.5h)
• Benchmark (30m)
• ClickHouse Keeper (1h)
• Iceberg (2h)
• LDAP (1h)
• Parquet (1.5h)
• RBAC (1.5h)
• SSL Server (1h)
• S3 (2h)
• Tiered Storage (2h)

[github-actions]

Workflow [PR], commit [ed37c4e]

[CarlosFelipeOR]

After this PR, the following regression tests started passing:

• /iceberg/iceberg engine/rest catalog/feature/show data lake catalogs in system tables
• /iceberg/iceberg engine/glue catalog/feature/show databases queries

Remaining failures in regression tests:

• Iceberg tests: After merging Antalya 25.8 Backport of #87095 - Fix simple parquet reader v3 assert on bool column min/max #1269, they should pass.
• Swarms, Parquet, and Export Part suites: These are not new failures, and the QA team is working on addressing them.

Additionally, these remaining integration test failures occur frequently and were not introduced by this PR.

Adding the verified label.