Easier importing of airo-mono functions/classes

[Victorlouisdg]

Describe the feature you'd like
Easier importing of airo-mono functions/classes. Currently to import airo-mono functions etc. you generally have to fully specify the import paths, e.g:

from airo_camera_toolkit.cameras.zed.zed2i import Zed2i
from airo_camera_toolkit.pinhole_operations.projection import project_points_to_image_plane

Specifying this can be a bit tedious and requires users to be aware of the entire structure of our Python packages.
Editor import suggestion tools can help with this, but currently this doesn't seem to work well for me in VSCode with Pylance and non-editable pip installed airo-mono, e.g:

transform_points() # here I get the suggestion Add "from airo_spatial_algebra import transform_points"
project_points_to_image_plane() # here I don't get import suggestions

Possible implementation

1. Move imports higher e.g. from airo_camera_toolkit import Zed2i, project_point_to_image_plane
2. Improve integration with import-suggestion tools

[m-decoster]

Overall, I agree, however:

from airo_camera_toolkit import Zed2i

Hardware related imports are tricky, because, e.g., importing Zed2i requires that the Zed python SDK is installed. See #110

This could maybe be avoided by only importing the hardware specific packages once the Zed2i or Realsense objects are constructed, but this is not always possible, e.g., https://github.com/airo-ugent/airo-mono/blob/main/airo-camera-toolkit/airo_camera_toolkit/cameras/zed/zed2i.py#L55