Fix typos in source comments and descriptions

archipack/archipack_cutter.py

archipack/archipack_fence.py

archipack/archipack_keymaps.py

archipack/archipack_manipulator.py

archipack/archipack_material.py

archipack/archipack_rendering.py

archipack/archipack_slab.py

archipack/archipack_wall2.py

blenderkit/download.py

blenderkit/paths.py

blenderkit/search.py

blenderkit/ui.py

curve_tools/Curves.py

curve_tools/ShowCurveResolution.py

curve_tools/cad.py

curve_tools/curve_remove_doubles.py

io_scene_fbx/export_fbx_bin.py

io_scene_gltf2/blender/exp/gltf2_blender_gather.py

io_scene_gltf2/blender/exp/gltf2_blender_gather_nodes.py

io_scene_gltf2/blender/imp/gltf2_blender_gltf.py