Can't cancel creating Wire Motor

[Krzeszny]

Describe the bug
When you start making a Wire Motor, you can't reset the tool. This is especially problematic if you missclick and start creating a motor on the wrong prop, which can be disastrous if you select a huge prop.

Also, the UI doesn't say that you click on an existing motor to update it.

To Reproduce

1. Have a prop nearby and Motor Tool (Wire)
2. Left-click on the prop once
3. Try to cancel. You can't.

Expected behavior
R or RMB to cancel
Additionally, updating existing motors could be done with RMB instead of LMB