backward compatibility with string calls and empty e2 return type

[AlexALX]

fix issue mention on #2841 - allow empty (void) return type when not required in non strict mode + fix check in other place, should be OR logic, not AND.

Test code is

@name 
@inputs 
@outputs 
@persist 
@trigger 

function number test() {
    return 1    
}

"test"()

[thegrb93]

Can you add a test case for this as well?

[thegrb93]

In data_static/expression2/tests

[AlexALX]

i'll recreate pull request, since did on old branch