feat: download assets subset

[jlahovnik]

If a regex expression is passed in the parameter asset in the download(), only the assets matching this expression are downloaded (only working if the provider API returns individual assets and not a zip file); implemented for the HTTPDownload and AwsDownload plugins (s3rest plugin not used anymore after removal of mundi).

Client mode usage:

path = dag.download(eo_product, asset=asset_key, **optional_download_kwargs)
# or
path = eo_product.assets[asset_key].download(**optional_download_kwargs)

Server mode usage:
http://127.0.0.1:5000/path/to/some/item/download/asset_key

Please note that EOProduct.assets is now initialized as an AssetsDict(UserDict).

[github-actions]

Test Results

       4 files  ±0         4 suites  ±0   3m 25s ⏱️ -1s
   433 tests +1     430 ✔️ +1    3 💤 ±0  0 ❌ ±0 
1 732 runs  +4  1 656 ✔️ +4  76 💤 ±0  0 ❌ ±0 

Results for commit 271d638. ± Comparison against base commit 9c1a67c.

♻️ This comment has been updated with latest results.

[github-actions]

Code Coverage (Ubuntu)

File	Coverage
All files	82%	✅

Minimum allowed coverage is 70%

Generated by 🐒 cobertura-action against 271d638

[github-actions]

Code Coverage (Windows)

File	Coverage
All files	76%	✅

Minimum allowed coverage is 70%

Generated by 🐒 cobertura-action against 271d638

[sbrunato]

Please filter assets keys instead of title or href

[jlahovnik]

Please filter assets keys instead of title or href

done