One of the problems with this construction is that it involves redundant words. Both of your example sentences for example, read better as:
'It seems that the government will impose a curfew.
It seems that the government will impose a curfew during the course of the afternoon.'
Where we use 'It seems to be that ...' it is to show that we are not really sure that our observation matches our understanding. In this sense, your idea that 'it turns out' is correct, but that only tells half the story.
For example I might remark 'It seems to be that Janet loves John'. This might mean 'It turns out that Janet loves John'; but it might also mean 'It looks as though Janet loves John, but I am not sure this is true.'
Thus the addition of 'to be' does nothing for the grammar or the obvious meaning of the sentence, but as is often the case with English, we add the words to not only give information, but also to say how we feel about that information.