refactor: URL params in Dashboard listing

[mrshu]

• Refactor the way URL params are being passed to requests in Dashboard listing in pull_dashboards.py, as the previous version has been susceptible to encoding issues.

Signed-off-by: mrshu mrshu@cisco.com

[one-data-cookie]

Thanks for this, @mrshu! ⭐

Shall we apply the same logic to get_datasets_from_superset and even get_datasets_from_superset, you think?

[one-data-cookie]

@mrshu I also updated the other functions using the same logic as mentioned in the previous comment. Thank you and merging!