Suggestion Manage Modules tab: show different hint/button when no modules are installed

[Taschenbuch]

current behavior:

• see screenshot below
• suggest manually installing modules
• button opens modules in windows explorer

suggested behavior:

• Show a different hint like "You dont currently have any modules. Install some modules via "Module Repo" Tab"
• remove button OR let it open the "Module Repo" tab instead

[Xander Lamkins]

Good ideas. Duplicate of #519. 🙂