cli: Terraform migrations on upgrade (#1685)

* add terraform planning

* overwrite terraform files in upgrade workspace

* Revert "overwrite terraform files in upgrade workspace"

This reverts commit 8bdacfb8bef23ef2cdbdb06bad0855b3bbc42df0.

* prepare terraform workspace

* test upgrade integration

* print upgrade abort

* rename plan file

* write output to file

* add show plan test

* add upgrade tf workdir

* fix workspace preparing

* squash to 1 command

* test

* bazel build

* plan test

* register flag manually

* bazel tidy

* fix linter

* remove MAA variable

* fix workdir

* accept tf variables

* variable fetching

* fix resource indices

* accept Terraform targets

* refactor upgrade command

* Terraform migration apply unit test

* pass down image fetcher to test

* use new flags in e2e test

* move file name to constant

* update buildfiles

* fix version constant

* conditionally create MAA

* move interface down

* upgrade dir

* update buildfiles

* fix interface

* fix createMAA check

* fix imports

* update buildfiles

* wip: workspace backup

* copy utils

* backup upgrade workspace

* remove debug print

* replace old state after upgrade

* check if flag exists

* prepare test workspace

* remove prefix

Co-authored-by: Otto Bittner <cobittner@posteo.net>

* respect file permissions

* refactor tf upgrader

* check workspace before upgrades

* remove temp upgrade dir after completion

* clean up workspace after abortion

* fix upgrade apply test

* fix linter

---------

Co-authored-by: Otto Bittner <cobittner@posteo.net>

cli/internal/upgrade/upgrade.go

@@ -0,0 +1,10 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+/*
+Package upgrade provides functionality to upgrade the cluster and it's resources
+*/
+package upgrade