Update ESCET IDE screenshots with new ESCET icon
We introduced a logo and icon for ESCET in #777 (closed). I forgot to then update various ESCET IDE screenshots in our repo, which all still show the dummy ESCET icon we used before that.
It concerns the following files, all of them end-user visible:
chi/org.eclipse.escet.chi.documentation/images/screenshot_ide.pngcif/org.eclipse.escet.cif.documentation/images/screenshot_ide.pngcif/org.eclipse.escet.cif.models/examples/synthesis/bridge/images/overview_simulation.pngreleng/org.eclipse.escet.releng.website/website/chi/chi-screenshot-ide.pngreleng/org.eclipse.escet.releng.website/website/cif/cif-screenshot-ide.pngreleng/org.eclipse.escet.releng.website/website/tooldef/tooldef-screenshot-ide.pngtooldef/org.eclipse.escet.tooldef.documentation/images/screenshot_ide.png