Adds star gears project to the library

[HungryProton]

Star gears is an MSEP project with motors and springs but the library only supports PDB files (atoms & bonds only).

This PR adds the ability to import full MSEP workspaces to the current workspace.

[MarianoGnu]

Why is there both star_gears.msep1 and star_gears.msep1.tres files? they are meant to be the same file, and tres is only a temporary file created during loading and save

[MarianoGnu]

Because the load process generates a .tres file in the same location as the .msep1 file we should test how this works after export, because the template file will reside inside of the MSEP.pck file.

The pdb/mol importer creates a copy of the file in a temp folder before actually importing it

[MarianoGnu]

nit: you can replace all this block for
out_workspace_context.clear_all_selection()

[HungryProton]

Because the load process generates a .tres file in the same location as the .msep1 file we should test how this works after export, because the template file will reside inside of the MSEP.pck file.

The pdb/mol importer creates a copy of the file in a temp folder before actually importing it

You're right, that doesn't work in exported builds. I'll see if I can move the tres file in another location.

[MarianoGnu]

Lets address in the next PR, Jonathan is asking to merge stuff