Expose Parameter properly (enum, int, range...)

Blocked by #96 and VST2 non-chunk deprecation

Currently in AU / LV2 / AAX / VST3 / VST2.4, parameters are explosed as 0..1 floats instead of their full range and labels and integer bounds.

As explained in the plan #517 , we need to get out of this as it makes impossible to remap a parameter without breaking user compatibility.

Fixing this is itself a breaking change for user compatibility and need an Option.

Start by reading the plan in #517 and the blocker in #96, then compare how parameters are exposed across AU, LV2, AAX, VST3, and VST2.4. The work is done when full ranges, labels, and integer bounds are exposed while the breaking behavior is guarded by an option; VST2 non-chunk deprecation remains a dependency.

Written by the indexing model from the issue text.