Add "not" and "not_in" filters for LAS dimensions

Currently, Giro3D allows the filtering of LAS point clouds, with comparison operators such as less and greater (see https://gitlab.com/giro3d/giro3d/-/blob/main/src/sources/las/filter.ts?ref_type=heads#L15).

While those are convenient for 'continuous' attributes such as Green or Z, they cannot easily be used to express filtering on enumerable dimensions like: "I want to filter points with Classification=0 or Classification=3".

This is why I propose to add new operators in and not_in, to express filtering on a discrete set of values.