Bug 186594

For the WPE port the inspector resources are bundled using for loading with
GResource, built into an shared library which contains the bundled data,
and finally loaded on-demand using GModule (which ends up using “dlopen”)
when first needed.

There are no other contents in the shared library, so we could as
well generate a “*.gresource” data file instead (which is a GVDB
file), and load it using “g_resource_load” (instead of using GModule).
There are a few small advantages:

 - Disk space savings. GDVB files are slightly more compact than
   a shared library, and are mmap'd when loaded.

 - Loading the data does not involve the dynamic linker (no need for
   parsing an executable object, resolving symbols, etc.).

 - No intermediate build steps: the XML manifest gets built into the
   .gresource data file directly (compare with the current approach,
   which is: XML manifest → C source → object file → shared library).

While there's nothing particularly important in the list above, it
still would be nicer to use a data file instead of a shared library
for the inspector resources.