Give more generous typings for `lowerBoundaries` and `upperBoundaries`

[tpoisseau]

use ArrayLike<number> instead number[]

for direct in this import import direct from 'ml-direct'

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Also it really need to properly types initialState and finalState

[tpoisseau]

PS: boundaries are wrapped with new Float64Array(boundary), array and typed array match ArrayLike so it's safe.

[targos]

We should start by migrating this project to TS