Is there a word for things that include w.c. pan, washbowl, bath tub, shower cabin etc?
You can call "fixtures", but it is a bit ambiguous because it includes every piece of furniture or equipment fixed in a house, which you cannot take with you when you move to another house. I think it's better and common to say in two words "sanitary fittings".
For American English:
These are usually called "fixtures." Those specific to handling water are "plumbing fixtures." Those specific to the bathroom are "bathroom fixtures." Those specific to handling bodily wastes (toilets and urinals) are known as "sanitary fixtures."
(Most people who aren't architects or contractors don't use these terms very much. Usually people call the fixtures by their individual names: "toilet," "tub," "kitchen (or bathroom) sink." Sometimes people will talk more generally about "the plumbing," which includes the plumbing pipes, valves, & etc. as well as the plumbing fixtures.)
In the US, the toilet is usually located in the bathroom, along with the bathroom sink, and the bathtub or shower stall. An American asking to "use the bathroom" almost invariably wants to use the toilet.
The only plumbing fixture commonly found in the kitchen is the kitchen sink. Other kitchen fixtures usually include the refrigerator, which is an electrical fixture; and the stove (sometimes called the "range"), which may be an electrical or a (natural) gas fixture.
Other household fixtures include electrical lighting fixtures and gas or electric heaters.
w.c. pan = toilet bowl (almost always joined to the toilet tank and just called the "toilet")
washbowl = sink
bath tub = bathtub
shower cabin = shower stall or just "shower"
(bidet = bidet, but they are so rare here that they may be most frequently referred to by: "What the heck is that thing?")
These are called "bathroom fixtures" (in America).
Of course, in America we don't have a w.c.—we have bathrooms, which include a fixture called the "toilet".
And we have never heard of these "sanitary fittings" mentioned in other answer. So it would be good to clarify what country you want terminology for.
In my country if you say you want to use the bathroom, they will think that you want to take a bath. WC is used mainly by Architects. The common word is toilet if you mean toilet and bathroom if you want to wash or take a bath or shower.