Add ensure spice to pointing frame and move to kernels.py

[laspsandoval]

Algorithm Description:

Requirements:

• The functions in pointing_frame_handler.py should be in the imap_processing/spice/kernels.py module.
• Add ensure spice decorator instead of mount path to efs and in other places currently using:

with spice.KernelPool(kernels):

The ensure_spice decorator is in place and I think should be used here. I pictured the input of this function to be a file path to the CK that should be used and that it would not contain any kernel furnishing code.

For your test, you can manually furnish only the kernels needed using fixture(s) similar to https://github.com/IMAP-Science-Operations-Center/imap_processing/blob/dev/imap_processing/tests/conftest.py#L44