simplify fuzzy module spec

load the po file in a beforeEach function, no need to duplicate that code
add support for statically evaluable arguments for gt calls

sometimes it is good to split up strings into multiple parts, to distribute
them over more than one line. This makes the code more readable, but of course
results in a syntax subtree, that can not be used.

This new feature provides support for cases, that only do static
transformations to the specific arguments to the gt calls. So if a specific
argument can be evaluated to a string without any other scope, the argument
is considered valid, now.
factor out handle method for actual gt calls

this will make it more easy to add support for the different cases to
initiate the gettext module
add support for modules using define.async extension

See https://github.com/Open-Xchange-Frontend/define.async - using this
method to define modules are now supported, too.