Refactor Livedata API to be cleaner and more flexible

Create namespaces so that the API is more organized

For instance:

logic.changeLayout
logic.filterAdd
logic.filterRemove
...

becomes:

logic.layout.change
logic.filter.add
logic.filter.remove
...

Change method parameters to objects

The goal is to get the API more flexible for now, but also for the future if we need to modify the parameters that a function takes.
For instance:

logic.getPropertyDescriptors()
logic.getFilterablePropertyDescriptors()
logic.getSortablePropertyDescriptors()

becomes:

logic.properties.getDescriptors({ filterable: true, sortable: true })

Change Livedata configuration object name to config instead of data

The logic object has the logic.data property that contains the whole Livedata configuration (query, data, meta). However, the term "data" is confusing for this object.

Also, fix some variable names so that it stays coherent across files.

Simplify the init method

The Logic.js init method uses WeakMap to create and bind the passed element to it corresponding Livedata instance.
Let's simply that by returning the Logic class instead!