variable backend URL

...app/components/analysis-panel/analysis-panel.component.ts

src/app/components/network/network.component.ts

...app/components/privacy-banner/privacy-banner.component.ts

src/app/config.ts

...dd-expressed-proteins/add-expressed-proteins.component.ts

src/app/services/analysis/analysis.service.ts

...app/services/netex-controller/netex-controller.service.ts

src/index.html