virtual-input-device/native: Emit discrete scroll when the source is a wheel
Previously, when scroll was received in a remote session, it was handled as continuous scroll.
This generated issues with clients without high-resolution scroll support as the code path in charge of accumulating scroll until 120 is reached was not used and therefore discrete scroll events were not being generated.
Handle scroll generated in a remote session as discrete scroll when the source is CLUTTER_SCROLL_SOURCE_WHEEL to fix this issue.
Fix #2473 (closed)
Fixes: 9dd6268d ("wayland/pointer: Send high-resolution scroll data")
cc @pnowack