Compile full distributable from from source

[nuschpl]

The file fetchDependencies.gradle
being part of build process contains references to multiple binary artefacts even for open source dependencies. This invalidates most advantages of building code from source.
Namely it:

• includes postgresql binary which should be compiled from source or used provided by operating system.
• reference to sourceforge hosted binary Java artefacts which should be compiled from source and hosted on Github
• references to FIDB files on ghidra-data repository which says in Readme.md that says 'this repisitory is designed more for human consumption than machine'. Additionally those are fetched build time, ideally those files should be hosted in same repository or handled by git submodule / git lfs to ease offline compilation of Ghidra.