Fix z-index order of GPX overlay + color class refactor#438

JammingBen merged 2 commits into

opencloud-eu:mainopencloud-eu/web-extensions:mainfrom

Cassolette:patch/gpx-z-and-color-class-refactorCassolette/opencloud-web-extensions:patch/gpx-z-and-color-class-refactorCopy head branch name to clipboard