Graffiti artist Banksy hopes to raise more than £3 million for the British National Health Service by selling his painting: "Hope," according to Sky News.     The painting, titled Game Changer, was delivered to Southampton General Hospital during the first wave of the pandemic, with a note saying: "Thanks for all you're doing... I hope this brightens the place up a bit, even if it's only in black and white."   Now the anonymous graffiti artist is putting the original painting up for sale to raise funds to support the British health authorities in the face of the pandemic.   The hand-drawn image shows a child playing with superhero dolls. While Batman and Spiderman are discarded in a wastepaper basket, the child holds a masked nurse figure in a cloak.   A copy of the work will remain in the hospital, according to the report translated by Ahwal Al-Ma'rifa.   Katherine Arnold, co-head of Post-War and Contemporary Art in Europe at Christie's, said: "At a time when we can dare to hope again and look to life after the pandemic, it is important to reflect on the many symbols of strength and hope that we have seen internationally since the beginning of 2020."