`plan` doesn't show exact reason for new release, if no resource changes

[alexey-gavrilov-flant]

Before proceeding

• I didn't find a similar issue

Problem

WERF_EXIT_CODE: "true"

We use werf plan to obtain information about what will change during werf converge, but if the previous rollout was unsuccessful but all changes were applied, werf plan issues a warning but also writes that there is nothing to change unnecessarily.

Solution (if you have one)

If diff is equal to 0, output raw data from nelm about the reason for the changes.

Additional information

Version: v2.55.5

[ilya-lesikov]

In case of "No resource changes planned, but still must install release" we can show the reason, why is it so.

It will be one of "manifests changed", "last release was not successful", etc. If applicable, the diff can be showed, e. g. in what way the manifests changed. This function encapsulates the logic to decide whether the Helm Release Secret is outdated.