Touchpad: allow simultaneous smartphone-like pinch zoom and pan gestures in darkroom#20812

da-phil wants to merge 5 commits intodarktable-org:masterdarktable-org/darktable:masterfrom

da-phil:touchpad_seamless_pinch_zoom_and_panda-phil/darktable:touchpad_seamless_pinch_zoom_and_panCopy head branch name to clipboard