feature(downloader): add option to control over stream mode

[Guts]

This PR introduces a new option QDT_STREAMED_DOWNLOADS to control over stream mode for file downloader. By default, files are streamed but it can lead to some errors. This setting helps to avoid buggy behaviors.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 86.66667% with 2 lines in your changes missing coverage. Please review.

Project coverage is 71.14%. Comparing base (240d9f2) to head (a660b08).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
qgis_deployment_toolbelt/utils/file_downloader.py	80.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #541      +/-   ##
==========================================
+ Coverage   71.08%   71.14%   +0.06%     
==========================================
  Files          47       47              
  Lines        3081     3091      +10     
  Branches      664      666       +2     
==========================================
+ Hits         2190     2199       +9     
  Misses        700      700              
- Partials      191      192       +1     

Flag	Coverage Δ
unittests	70.52% <86.66%> (+0.06%)	⬆️

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Files with missing lines	Coverage Δ
qgis_deployment_toolbelt/commands/deployment.py	70.58% <100.00%> (+0.43%)	⬆️
qgis_deployment_toolbelt/commands/upgrade.py	62.63% <ø> (ø)
...deployment_toolbelt/jobs/job_plugins_downloader.py	50.75% <100.00%> (+0.75%)	⬆️
...eployment_toolbelt/profiles/remote_http_handler.py	36.53% <100.00%> (+2.53%)	⬆️
qgis_deployment_toolbelt/utils/file_downloader.py	75.51% <80.00%> (+0.51%)	⬆️

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud