add DishkaRouter for integrations/litestar.py

[chesnokpeter]

Similar to fastapi, i added DishkaRouter to get each handler to not need to hang @inject on every handler

from dishka.integrations.litestar import (
    FromDishka,
    LitestarProvider,
    inject,
    setup_dishka,
    DishkaRouter,
)
    
@post('/')
async def general(gateway: FromDishka[Gateway]) -> Response:
    ...

r = DishkaRouter('', route_handlers=[general])

def create_app() -> Litestar:
    app = Litestar(route_handlers=[r])
    setup_dishka(container, app)

[Tishka17]

not related to PR
anyway, we do not use lock here as we develop library

[Tishka17]

• Tests
• Can in be used with websockets?
• Can it be used with nested routers?