Update `influxdb3_client` and `influxdb3` Query CLI to support optional database for InfluxQL

The purpose of this issue is to give the `influxdb3_client` and `influxdb3` Query CLI the means to handle the optional `database` parameter, as it can be specified in the query string provided.

#### Current Behaviour

The `database`/`db` parameter is required in both the `influxdb3_client` and in the `query` CLI sub-command.

#### Desired Behaviour

* `influxdb3_client` should be able to compose a request to `api/v3/query_influxql` without a `db` parameter
* `influxdb3 query` sub-command should make the `--db_name` optional when `--lang` is set to `influxql`

Start with the influxdb3_client request construction for api/v3/query_influxql and the influxdb3 query sub-command's --db_name validation. Trace how InfluxQL query-string parameters are handled, then verify that requests can omit db and that --db_name is optional only when --lang is influxql.

Written by the indexing model from the issue text.