Add an option to forward all clicks

Add --forward-all-clicks to disable mouse shortcuts and forward middle
and right clicks to the device instead.

Fixes #1302 <https://github.com/Genymobile/scrcpy/issues/1302>
Fixes #1613 <https://github.com/Genymobile/scrcpy/issues/1613>

README.md

@@ -595,6 +595,16 @@ scrcpy --no-key-repeat
 ```
 
 
+#### Right-click and middle-click
+
+By default, right-click triggers BACK (or POWER on) and middle-click triggers
+HOME. To disable these shortcuts and forward the clicks to the device instead:
+
+```bash
+scrcpy --forward-all-clicks
+```
+
+
 ### File drop
 
 #### Install APK