X / originalX

Currently we store 2 values in peaks: `x` and `originalX`.

```json
{
"id": "1SMdLJ6q",
"originalX": 3.8314013767193043,
"x": 3.8314013767193043,
"y": 67533497,
"width": 0.9138402540488912
}
```

The difference between the 2 is the 'shift' filter that can be applied to set correctly the reference in the spectrum.

It is probably important to store in the file the 'corrected' value (`x`) because this is what you would like in order to make queries in the database.

I would prefer to get rid of this `originalX` property because it requires to maintain 2 values (when optimizing peaks for example).

## What does it implies ???

I guess the main issue is when we change the `shiftX` filter. All the 'peaks' need to be changed by the difference value.

Of course this will also apply to `zone` and `range`

@hamed-musallam @jobo322 What do you think ?