Support uninstallation for kyma in the installer

[piotrmsc]

Description

Currently, it is possible to trigger uninstallation of kyma via kyma-installer using action label on the installation CR. However, it does not work officially and as expected. For example, see here #1826. Kyma installer should support this action properly, by invoking helm delete (with probably --purge option) on all resources installed by the installer. Documentation should be updated as well and cover this topic fully - users should know how to uninstall kyma to be able to install it again without the need to delete the cluster.

Uninstallation should be triggered using the same CR used for installation. Handling of multiple CRs with installation kind will be handled in the future.

Installer should report releases that failed to uninstall (preferably in installation CR).

Unfortunately, it is not possible to label releases so we have to accept resources provided in the CR and delete it, without checking if it belongs to kyma. Kyma installer (or operator is more accurate name) will be able to uninstall any chart in the cluster. At least for now.

Reasons

It's is beneficial to have a full install/upgrade/uninstall flow supported.

Attachments

[derberg]

Very good issue, I like it as now in GCP if you install Kyma through marketplace, it is not possible to uninstall without whole cluster deletion

[Demonsthere]

From what I can see purge is enabled by default in the installer already

[rufreakde]

this link is broken?