EVG-15628: use Go modules

[Kimchelly]

Jira:
https://jira.mongodb.org/browse/EVG-15628

I don't think Evergreen will be able to test this PR because it's such a large diff. I tried testing out most of the targets locally and they succeeded.

• Use Go modules and remove vendored dependencies. Instead, the dependencies for our repositories will be dynamically fetched during runtime using go mod tidy.
• Upgrade dependencies to the newest minor version. This is somewhat risky since we have outdated dependencies, but I would prefer to take the pain of upgrading them as much as possible now since we'll eventually have to upgrade our dependencies anyways. I'm going to assume that repos are obeying semantic versioning, so minor version upgrades are supposed to be backwards compatible.
• Update README for modules instead of vendoring.
• Update and standardize the Evergreen YAML file. The GOMODCACHE is set because for CI tests, it's better to not write outside of the agent working directory for Evergreen since it won't clean it up.