Linting of timer definitions are incomplete

[nazlikaya]

At the moment, we only check if the "timer definiton" field is filled, but not if the value is excepted. That is why when user tries to deploy, they got an error, even if the linting says there is no error.
Expectation: Linting covers this type of errors, so that when it is green, it really means user can deploy without a problem.

[nazlikaya]

I am not sure it should be fixed in linting or in properties panel as we do it for other input fields.