RemoteLinux: Separate file transfer out of LinuxDevice

... into a new file pair again.

The interface is essentially just SshConnectionHandle.

Change-Id: I115fcefbfca4606c6440f97efb3e71121c87ee52
Reviewed-by: Christian Kandeler <[email protected]>

Author: HkJot

src/plugins/remotelinux/CMakeLists.txt

@@ -21,6 +21,7 @@ add_qtc_plugin(RemoteLinux
     remotelinuxdebugsupport.cpp remotelinuxdebugsupport.h
     remotelinuxdeploysupport.cpp remotelinuxdeploysupport.h
     remotelinuxenvironmentaspect.cpp remotelinuxenvironmentaspect.h
+    remotelinuxfiletransfer.cpp remotelinuxfiletransfer.h
     remotelinuxplugin.cpp
     remotelinuxrunconfiguration.cpp remotelinuxrunconfiguration.h
     remotelinuxsignaloperation.cpp remotelinuxsignaloperation.h