Allowed to save new composition with a name that already exists

Found issue:

Saved effects can easily be overwritten by accidentally saving a new effect with existing name.

Steps to reproduce:

• Create effect with Effect Compser
• Click "Save current composition"
• Give name "MyEffect" and save
• In Effect Composer, click + (Add new composition)
• Add some effect and click "Save current composition"
• Give the same name, "MyEffect" and save
• ->previously created effect is overwritten by the new one
• -> would be nice to have some notification that effect with this name already exists, and if the user still wants to proceed with saving / overwrite the existing effect