[SCI-9938] loading spinner now remains visible even when screen is scrolled
[SCI-9938] loading spinner now remains visible even when screen is scrolled

DiamondLightSource/SynchWeb,DiamondLightSource/SynchWeb,DiamondLightSource/SynchWeb,DiamondLightSource/SynchWeb,DiamondLightSource/SynchWeb,DiamondLightSource/SynchWeb