[Verif] Allow for `disable` to be optional and infer it from property

[dobios]

This PR modifies the verif::clocked_assertlike ops to allow for the disable to be optional. In the case where it is omitted, it will be inferred from the property itself following the folding patterns defined in LTLToCore, i.e.

• property = disable: i1 OR prop : !ltl.property for assume and assert ops
• property = NOT(disable: i1) AND prop : !ltl.property for cover ops.

This should allow us to get rid of ltl.disable in the new redesign of ltl