query tags integration (#927)

## Description
This PR adds **Query Tags** support to the JDBC driver. Users can now
attach labels to their SQL queries for analytical purposes. Tags follow
the format `key1:value1,key2:value2"` and appear in the
`system.query.history` table.

### Changes Made:
- **Added `QUERY_TAGS`** to the list of allowed session configurations
in `DatabricksJdbcConstants.java`

### How to Use:
- URL: jdbc:databricks://host;QUERY_TAGS=team:marketing,dashboard:abc123
- Properties: properties.put("QUERY_TAGS",
"team:engineering,project:pipeline")

## Testing
- Tested manually by creating a connection with query tags passed as
connection property and verified that they're sent to the backend
successfully, and appear in the system.query.histroy table

## Additional Notes to the Reviewer
- Works with both Thrift and SEA modes
- Backward compatible - existing connections work unchanged

### Future Plans:
- **Statement-level tags** will be added later (currently session-level
only)

---------

Signed-off-by: Sreekanth Vadigi <sreekanth.vadigi@databricks.com>

Author: sreekanth-db

NEXT_CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 ### Added
+- **Query Tags support**: Added ability to attach key-value tags to SQL queries for analytical purposes that would appear in `system.query.history` table. Example: `jdbc:databricks://host;QUERY_TAGS=team:marketing,dashboard:abc123`. 
 
 ### Updated
 

src/main/java/com/databricks/jdbc/common/DatabricksJdbcConstants.java

@@ -81,7 +81,8 @@ public final class DatabricksJdbcConstants {
           "READ_ONLY_EXTERNAL_METASTORE", "false",
           "STATEMENT_TIMEOUT", "0",
           "TIMEZONE", "UTC",
-          "USE_CACHED_RESULT", "true");
+          "USE_CACHED_RESULT", "true",
+          "QUERY_TAGS", "");
   public static final Set<String> ALLOWED_CLIENT_INFO_PROPERTIES =
       Set.of(
           ALLOWED_VOLUME_INGESTION_PATHS,

src/test/java/com/databricks/jdbc/api/impl/DatabricksConnectionTest.java

@@ -472,4 +472,15 @@ void testHoldability() throws SQLException {
     assertThrows(
         DatabricksSQLFeatureNotSupportedException.class, () -> connection.setHoldability(3));
   }
+
+  @Test
+  public void testQueryTagsInSessionConfigs() throws SQLException {
+    String queryTagsJdbcUrl = JDBC_URL + ";QUERY_TAGS=team:marketing,dashboard:abc123";
+    IDatabricksConnectionContext connectionContext =
+        DatabricksConnectionContext.parse(queryTagsJdbcUrl, new Properties());
+
+    Map<String, String> sessionConfigs = connectionContext.getSessionConfigs();
+    assertTrue(sessionConfigs.containsKey("query_tags"));
+    assertEquals("team:marketing,dashboard:abc123", sessionConfigs.get("query_tags"));
+  }
 }