enable trust-dns feature for reqwest crate for more reliable dns resolution

[reubenmiller]

Proposed changes

Use trust-dns feature of the request crate to improve the robustness to invalid DNS nameservers.

TODO:

• Add system tests to replicate invalid DNS nameservers
• State advantages for using tedge-dns
• Check if the added dependencies is ok
• Check if there are some other subtle negative impacts of this change, or if a different retry error makes more sense

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

#2321

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
312	0	3	312	100	53m14.577999999s

[albinsuresh]

This reqwest crate is used only by a few crates in our repo like the downloader crate. The major ones like c8y_http_proxy use hyper directly. So, this might only partially solve the problems.

[reubenmiller]

There seems to be some support for hyper and trust-dns:

• https://crates.io/crates/hyper-trust-dns

But yes we should do a more comprehensive assessment so that it is consistent.