toggle seed nodes in analysis network

...p/components/analysis-panel/analysis-panel.component.html

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

...app/components/network-legend/network-legend.component.ts

src/app/config.ts

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

src/app/interfaces.ts

src/app/network-settings.ts

src/app/pages/explorer-page/explorer-page.component.ts