Refactor E2E suite to make it more generic

[alexander-demicev]

What this PR does / why we need it:
This PR is a part of the E2E refactoring issue, it includes the following changes:

• Our suite setup includes a lot of duplicate code for setting up management clusters on different infrastructures, I moved all related code to the testenv package. Any potential users of this code can reuse it or take it as an example and implement their own in case their e2e suite setup differs from ours.
• Some E2E configuration options are passed partially through ginkgo flags and the YAML config. I started moving some options from flags to config files so we have a single place for most configurations. I will open a follow-up PR with moving other values too.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

Checklist:

• squashed commits into logical changes
• includes documentation
• adds unit tests
• adds or updates e2e tests

[furkatgofurov7]

Thank you for PR, 2 comments inline:

[salasberryfin]

Thanks, this looks great.

[furkatgofurov7]

Suggested change

	// PreRancherTurtlesInstallHook is a hook that can be used to perform actions before Rancher Turtles is installed.
	// PreRancherTurtlesUpgradelHook is a hook that can be used to perform actions before Rancher Turtles is upgraded.

[Danil-Grigorev]

I'm leaving the approval as it "needs to be dirty and quick" but leaving some suggestions.

[alexander-demicev]

@Danil-Grigorev @furkatgofurov7 I will address typos/naming comments in a follow-up PR