Align query db description with other database commands (nushell#16680)

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Closes nushell#10243.
`query db` is the only command that doesn't state "SQLite" in the main
description (aside from `stor reset`).

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N/A

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- [ ] Update the
[documentation](https://github.com/nushell/nushell.github.io) (although
I think this is auto-generated for commands)

Author: Sheape

crates/nu-command/src/database/commands/query_db.rs

@@ -28,7 +28,11 @@ impl Command for QueryDb {
     }
 
     fn description(&self) -> &str {
-        "Query a database using SQL."
+        "Query a SQLite database with SQL statements."
+    }
+
+    fn extra_description(&self) -> &str {
+        "This command is only supported for local or in-memory SQLite databases."
     }
 
     fn examples(&self) -> Vec<Example<'_>> {