[3.x] Add double_tap attribute to InputEventScreenTouch

[m4gr3d]

This provides parity with the InputEventMouseButton allowing for proper conversion between the two events.

Address #67033

master version

[RandomShaper]

I'm testing it at the moment. I'm doing a few changes to have it working 100% correctly. Sadly, run out of time today. Tomorrow I'll report.

[RandomShaper]

These are the changes I'd like to suggest:
patch.txt

Without them, the timing of some down/up events is wrong and also the second tap in a double tap could get stuck.

Besides that, the only concern would be that the new double_tap field is not filled reliable across all the platforms, but that could be addressed separately.

[m4gr3d]

These are the changes I'd like to suggest: patch.txt

Without them, the timing of some down/up events is wrong and also the second tap in a double tap could get stuck.

Besides that, the only concern would be that the new double_tap field is not filled reliable across all the platforms, but that could be addressed separately.

@RandomShaper The patch looks good! I'll apply it and update the PR.

[m4gr3d]

@RandomShaper Updated! Can you review the changes. If this looks good, I'll forward-port the changes to the master branch.