fix: vertex tool schema validation

[arturfromtabnine]

fix for #1473
Description: (required)

• Refactored recursivelyDeleteUnsupportedParameters in Vertex AI utils to use an allowlist approach instead of a blocklist for filtering JSON Schema fields
• Created VERTEX_AI_SUPPORTED_SCHEMA_FIELDS Set containing all fields supported by Vertex AI's Schema API (type, format, title, description, properties, items, anyOf, enum, required, etc.)
• Added support for converting array type definitions to anyOf format (e.g., {"type": ["string", "number"]} → {"anyOf": [{"type": "string"}, {"type": "number"}]}) since Vertex AI doesn't support type arrays
• Improved recursive handling with filterSchemaFields function that correctly distinguishes between schema objects and property maps to avoid incorrectly filtering property names
• Properly handles nested structures: properties maps, items schemas, anyOf arrays, and other nested schema objects

Tests Run/Test cases added: (required)

• Removes unsupported meta fields ($schema, $id, $comment)
• Removes additionalProperties
• Removes unsupported composition keywords (oneOf, allOf, not, const, if/then/else)
• Removes unsupported array keywords (uniqueItems, contains)
• Preserves all supported Vertex AI schema fields (type, format, title, description, nullable, default, example, properties, items, enum, required, min/max constraints, pattern, etc.)
• Recursively processes nested objects and arrays
• Correctly handles anyOf arrays
• Handles null and non-object values gracefully
• Converts array type to anyOf format
• Handles nested array types in complex schemas

Type of Change:

• 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 to not work as expected)
• Documentation update
• Refactoring (no functional changes)