remove corrupt cache files and retry download 3 times

[blackliner]

Changelog: Feature: Validate checksum and retry download for corrupted downloaded cache files.
Docs: omit

For testing, it would be cool if this feature could be switched on&off (default on), so the old test could remain with the feature switched off. Or mocking the Server to actually deliver corrupt files could also be an option to improve test coverage of the functionality.

I am also unsure about the logging, I have seen quite a multitude of ways to inform the user, from using the python logging, to _out.warn up to custom actions in a queue 🤔

Issue: #8807

• Refer to the issue that supports this Pull Request.
• If the issue has missing info, explain the purpose/use case/pain/need that covers this Pull Request.
• I've read the Contributing guide.
• I've followed the PEP8 style guides for Python code.
• I've opened another PR in the Conan docs repo to the develop branch, documenting this one.

^{Note: By default this PR will skip the slower tests and will use a limited set of python versions. Check here how to increase the testing level by writing some tags in the current PR body text.}

[CLAassistant]

All committers have signed the CLA.

[memsharded]

The file_downloader.download() already implements a retry following user configuration, and if it finally doesn't succeed, it will raise anyway, so the for loop will not iterate again. So the proposed iteration was not exactly achieving a retry. I have realized that it is enough to check for corruption first, remove if corrupted and then call download. Such download will try to download and validate checksum up to X times (typically 3)

[blackliner]

@memsharded thats amazing, thanks for the commit! Anything else I need to do to get this merged? Documentation?

[memsharded]

@memsharded thats amazing, thanks for the commit! Anything else I need to do to get this merged? Documentation?

Nop, it is fine, as this could be considered a good/better natural behavior of the download cache, I think it is not necessary to document it, I have read https://docs.conan.io/en/latest/configuration/download_cache.html, and seems we are good.

Assigned it to next 1.36.