Use internal function inside and inside_meshgrid' methods

[marc-flex]

          So every geometry (so including `Box`) has an [inside](https://github.com/flexcompute/tidy3d/blob/948098a3940500b7dee71cdefe5bd94600717378/tidy3d/components/geometry/base.py#L89) and [inside_meshgrid](https://github.com/flexcompute/tidy3d/blob/948098a3940500b7dee71cdefe5bd94600717378/tidy3d/components/geometry/base.py#L179) method. Can these be used directly instead of this? It seems like this handles some special cases but wondering if you've considered those.

Originally posted by @momchil-flex in #2205 (comment)