Allows the input of decal items in the texture tool

This patch allows users to just input a decal asset instead
of manually having to find the image asset. It uses an external
web API by F3X to extract the right image ID.
Allows the input of arbitrary mesh-containing assets in the mesh tool

This patch allows users to just input any asset containing a mesh
instead of manually having to find the mesh's ID. It uses an external
web API by F3X to extract the right mesh data from the given asset.
Merge branch 'feature/content-extraction' into development