[PTFM-7855] dxpy: Supply platform information in UA string; configurable UA extensions
[PTFM-7855] dxpy: Supply platform information in UA string; configurable UA extensions

olegnev/dx-toolkit,johnwallace123/dx-toolkit,jhuttner/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,olegnev/dx-toolkit,jhuttner/dx-toolkit,johnwallace123/dx-toolkit,dnanexus/dx-toolkit,johnwallace123/dx-toolkit,jhuttner/dx-toolkit,andyshinn/dx-toolkit,andyshinn/dx-toolkit,olegnev/dx-toolkit,andyshinn/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,jhuttner/dx-toolkit,dnanexus/dx-toolkit,johnwallace123/dx-toolkit,olegnev/dx-toolkit,johnwallace123/dx-toolkit,andyshinn/dx-toolkit,andyshinn/dx-toolkit,olegnev/dx-toolkit,johnwallace123/dx-toolkit,andyshinn/dx-toolkit,olegnev/dx-toolkit,andyshinn/dx-toolkit,jhuttner/dx-toolkit,olegnev/dx-toolkit,dnanexus/dx-toolkit,jhuttner/dx-toolkit,johnwallace123/dx-toolkit,dnanexus/dx-toolkit,jhuttner/dx-toolkit,andyshinn/dx-toolkit,jhuttner/dx-toolkit,olegnev/dx-toolkit,johnwallace123/dx-toolkit