Napalm proxy better error handling

[garethgreenaway]

What does this PR do?

Napalm proxy better error handling

What issues does this PR fix or reference?

Fixes: #62435

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• [ ] Docs
• [x] Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• [x] Tests written/updated

Commits signed with GPG?

Yes

Please review Salt's Contributing Guide for best practices.

See GitHub's page on GPG signing for more information about signing commits with GPG.

[s0undt3ch]

Can we also upgrade the napalm dependency? ... Since we're at it...