I skimmed the constitution of my country (Italy) and there is no collective term. There is a section "Organization of the Republic" that lists the several components (Parliament, President, Government, etc.) When we say Government we refer only to the Prime Minister, the other Ministers and their staff.
I am not sure. In French that would be the state (L’État). It’s more complicated in the U.K., with its layers of national, devolved country, and local governance. Then, it would be different again in federations like Germany.
In the US "government" generally refers to all three branches; is that not the case in Europe?