Action config validation may prevent models being saved
Problem/Motivation
Since we've introduced the validation of action configuration by executing the validate and submit callbacks in \Drupal\eca\Entity\Eca::addAction we're able to prevent invalid model from being saved as config entities.
However, the problem is that our extensive support of tokens may prevent validation although being perfectly OK, when the used token will contain the proper value when being processed later.
Example: the Send email action plugin validates that the Recipient email address field either contains a valid email address or a token that contains :mail.
Other validations may fail for different reasons.
Proposed resolution
Don't know what we should do about this. Either validate configuration or always save models regardless of validation. There doesn't seem to be any middle ground. Suggestions?