Treat Redirected Go Packages as Removed

[mikeyoung85]

This PR updates the check_status logic for Go packages to treat a redirect from pkg.go.dev as a "Removed" package. The reasons for this change are to help capture when packages are renamed or recased and mark the now incorrect one appropriately. This is just an idea, so feel free to disagree with this approach.

One example is:
https://libraries.io/go/github.com%2FAzure%2Fazure-pipeline-go vs https://libraries.io/go/github.com%2Fazure%2FAzure-pipeline-go which both reference github.com/Azure/azure-pipeline-go. This PR would mark github.com/azure/Azure-pipeline-go as removed.

> url = "https://pkg.go.dev/github.com/azure/Azure-pipeline-go"
> response = Typhoeus.get(url)
> response.response_code
=> 302
> response.body
=> "<a href=\"/github.com/Azure/azure-pipeline-go\">Found</a>.\n\n"

[jhan217]

Based off the logic in the description, should all packages that redirect be marked as "Removed"?

Also, maybe not for this PR, but thoughts about moving the platform specific statusing logic into their own classes vs a giant if/elsif/else statement?

[tiegz]

Based off the logic in the description, should all packages that redirect be marked as "Removed"?

pkg.go.dev is a little opaque, but based on my observations: if people move a Go Module, the package still shows up on "pkg.go.dev", so they file a PR with golang to remove that package. This works, but the golang team seems to recommend putting a "retract" statement for all the old versions in the new location's go.mod, which will then remove the old location from "pkg.go.dev", e.g. golang/go#62726 (comment)

based on that, it seems safe to mark these as "Removed", until we have some sort of redirection state in Libraries to note the new locations.

Also, maybe not for this PR, but thoughts about moving the platform specific statusing logic into their own classes vs a giant if/elsif/else statement?

we could replace check_status_url with a check_status in each package manager adapter class, and implement it there?

[jhan217]

🎱 Thoughts about cleaning up the specs to standardize the mocking / separate out the setup from the test expectations?

[tiegz]

this change seems fine, although I don't think it'll cover 100% of badly cased packages. For instance here's a valid Go Module (has a go.mod) where I've entered the wrong casing on pkg.go.dev, but pkg.go.dev still serves up the package without a redirect:

https://pkg.go.dev/github.com/go-sql-driver/mysQL

(but maybe we've fixed the Go ingestor far enough that it'll use the proper name github.com/go-sql-driver/mysql instead when ingesting?)