Squish is required by RTA for testing.

Task-number: QTQAINFRA-1523
Change-Id: I0c3653565f19cc9b798a0b63325c47b017cf5537
Reviewed-by: Joni Jäntti <joni.jantti@qt.io>
Reviewed-by: Matti Paaso <matti.paaso@qt.io>

Common shared folder includes scripts of files which are common for all
operating system families. Changes under shared folder will trigger
provisioning for all platforms

Change-Id: I0789f87b76876d5f92673fe2f0e72d770e5f5ea4
Task-number: QTQAINFRA-1451
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@qt.io>

Currently when adding an environment variable in provisioning we have
to check if the system is Ubuntu and use .profile instead of .bashrc.
This check should be done in a function so we don't have to duplicate
it for every provisioning script separately.

Change-Id: I2fa128032123e17d20dfb39cd3668e22e4bb0d55
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>

This change will split common folder to four different folders:
Linux, Unix, Windows and MacOS. Each of these folders includes scripts
which are common for their operating system familes

Task-number: QTQAINFRA-1451
Change-Id: Ic93b2183052335dee875d1452b21e38d268b6474
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@qt.io>