In VirtualBox 7 and recent 6.1 versions, the VMMDev is used to report
all mouse events if guest additions are used. Therefore, the
implementation aggregates these events, notifies the guest. and passes
the state on guest request. Unfortunately, the protocol does not support
to report consecutive button press and release events that may happen
between two guest requests, which results in events getting lost.
This commit patches the contrib sources to track pending mouse-button
events and notifies the guest if further state changes are pending after
updates are delivered.
Also, mouse-wheel events (dw, dz) are now accumulated between two guest
updates.
Fixes#5333
fa267ecbb3