Single effect/chain effects presets override each other if they have the same name

[David Corrales]

The single effects presets should be logically different from chain effects. In reality, you can't have a preset called TEST for chain effects and another one named TEST also for a single effect. The newest one will overwrite the old one.

Steps:
- Create an effect chain presets for a determined type of instrument, name it TEST.
- Crete a single effect preset for any effect and name it TEST.

Outcome:
- The single effect preset will overwrite the effect chain preset.

Expected result:
- An effect chain preset called TEST, along with a single effect preset called TEST also.

[David Corrales (davidcorrales)]

Thanks to Elleo I was able to commit a patch :)