Block actions with ChannelName executors

[josefkarasek]

Description

Changes proposed in this pull request:

• Block actions with ChannelName executors

Testing

Define a executor with ChannelName RBAC policy:

executors:
  k8s-default-tools:
    botkube/helm:
      enabled: true
      config:
        defaultNamespace: "default"
        helmDriver: "secret"
        helmConfigDir: "/tmp/helm/"
        helmCacheDir: "/tmp/helm/.cache"
      context: &default-plugin-context
        defaultNamespace: "default"
        rbac:
          group:
            type: ChannelName

actions:
  'describe-created-resource':
    enabled: true
    displayName: "Describe created resource"
    command: "kubectl describe {{ .Event.Kind | lower }}{{ if .Event.Namespace }} -n {{ .Event.Namespace }}{{ end }} {{ .Event.Name }}"
    bindings:
      sources:
        - k8s-create-events
      executors:
        - k8s-default-tools

Such action config should be blocked by config validator.

Related issue(s)

#1045

[mszostok]

Overall LGTM but I will leave final testing and approving for selected reviewer 👍

[josefkarasek]

Example faulty actions:

2023/05/15 14:53:51 while merging app configuration: found critical validation errors: 4 errors occurred:
	* Key: 'Config.Actions[describe-created-resource].Bindings.k8s-default-tools' Plugin botkube/kubectl has 'ChannelName' RBAC policy. This is not supported for actions.
	* Key: 'Config.Actions[describe-created-resource].Bindings.k8s-default-tools' Plugin botkube/helm has 'ChannelName' RBAC policy. This is not supported for actions.
	* Key: 'Config.Actions[show-logs-on-error].Bindings.k8s-default-tools' Plugin botkube/kubectl has 'ChannelName' RBAC policy. This is not supported for actions.
	* Key: 'Config.Actions[show-logs-on-error].Bindings.k8s-default-tools' Plugin botkube/helm has 'ChannelName' RBAC policy. This is not supported for actions.

[huseyinbabal]

As a general comment, so user just saw that message after they use actions with executors with channel RBAC, then what to do next? If they duplicate that without channel RBAC to use with actions, it will be a security concern for them. If we will introduce a support for actions then better to state that maybe? Any valuable link to our existing actions page would be valuable, of course we need to have a scenario for this.