bitbake: toaster: rename bldviewer projecttags custom tagset

bitbake: toaster: rename bldviewer projecttags custom tagset

We rename the projecttags in bldviewer.templatetags to
simple_projecttags in order to avoid conflict with the
similarly named tagset in toastergui.

The conflict leads to an intermittent bug where proper
tags are not read correctly since Django uses only the
module name as global tag library identificator.

(Bitbake rev: a37f2c194d7e59611177cb8755524b7ad702fe91)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>