Improve right click behavior

[Rokt33r]

Currently, the current desktop is providing very limited functionality like basic navigation, reloading pages, and opening dev tools. It should provide much more versatile options just like browsers do.

Specs

Specs are not ready yet. If you have any ideas, please leave some comments on this issue. It would be really helpful to finalize the specs faster.

General menu items

• Back
• Foward
• Reload
• ----
• Go to Home
• ----
• Developers
  • Hard Reload
  • Toggle Dev Tools

Right-clicking on image elements

• Save Image As
• Copy Image
• Copy Image Address
• Open Image In Browser
• ----
• ... All general items

Right-clicking on link elements

• Copy
• Copy Link Address
• Open Link In Browser
• ----
• ... All general items

Right-clicking on markdown editor

• ... TBD

Right-clicking on markdown preview

• ... TBD