added show_progress functionality for download

[Magnus167]

Now shows ETAs and progress bars for

with JPMaQSDownload(...) as client:
    df = client.download(... show_progress=True)

(default is False).
eg. :

2023-01-18T01:34:43.620624  UTC
Number of expressions requested : 1000
Requesting data :  44%|███████████              | 22/50 [00:08<00:13,  2.11it/s]

↓

2023-01-18T01:34:43.620624  UTC
Number of expressions requested : 1000
Requesting data : 100%|█████████████████████████| 50/50 [00:17<00:00,  2.83it/s]
Downloading data :  34%|████████▏               | 17/50 [00:30<00:23,  1.43it/s]

↓

2023-01-18T01:34:43.620624  UTC
Number of expressions requested : 1000
Requesting data : 100%|█████████████████████████| 50/50 [00:17<00:00,  2.83it/s]
Downloading data : 100%|████████████████████████| 50/50 [00:50<00:00,  1.04it/s]