Fix subquery references

[StpMax]

Description

Fix correlated subquery references being stripped in query_dfs

adapt_query in query_dfs was stripping all multi-part identifiers to just the column name (a1.tab_num → tab_num), which broke correlated subqueries. For example, WHERE a2.tab_num = a1.tab_num became WHERE tab_num = tab_num — that made NOT EXISTS and EXISTS produce identical results.

The fix collects the actual schema/database names from the FROM clause before traversal, and only strips identifiers whose first part matches a known schema — leaving table alias references (a1.col, b.shop) intact for DuckDB to resolve correctly.

-- Before fix: correlated reference lost
WHERE a2.tab_num = a1.tab_num  →  WHERE tab_num = tab_num

-- After fix: alias preserved
WHERE a2.tab_num = a1.tab_num  →  WHERE a2.tab_num = a1.tab_num
files.a1.tab_num               →  a1.tab_num

Fixes #11763 FQE-1690

Type of change

(Please delete options that are not relevant)

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ⚡ New feature (non-breaking change which adds functionality)
• 📢 Breaking change (fix or feature that would cause existing functionality not to work as expected)
• 📄 This change requires a documentation update

Verification Process

To ensure the changes are working as expected:

• Test Location: Specify the URL or path for testing.
• Verification Steps: Outline the steps or queries needed to validate the change. Include any data, configurations, or actions required to reproduce or see the new functionality.

Additional Media:

• I have attached a brief loom video or screenshots showcasing the new functionality or change.

Checklist:

• My code follows the style guidelines(PEP 8) of MindsDB.
• I have appropriately commented on my code, especially in complex areas.
• Necessary documentation updates are either made or tracked in issues.
• Relevant unit and integration tests are updated or added.

[ea-rus]

the query is almost the same as in test_multi_table_relational_division
maybe we can reuse that test?

[StpMax]

They are similar, but not exactly the same. I think it would be better to separate them than to link the files with additional imports.