Upgrade JUICE documentation examples to CReMA 5.1 (150lb, v400) trajectory

A new release v400 of the JUICE SPICE kernels are now available and includes the latest excepted launch window in April 2023 (5.1 150lb).

These new kernels support the new SWITCH FRAME kernels (#56 (closed)).

Changes

• all the docs/ and examples/ were updated to taken into account this trajectory.
• docs kernels trimmer was updated to take into account the new kernels.

Addition

• new dsk and pck kernels trimmer (with NAIF mkdsk utility)

Fixes

• Kernel data with = sign in string value and empty assignation can now be parsed with get_data().
• pathlib.Path and += assignation symbol can be used in kernel format_data().
• Bump2version config (date formatting in .cfg file).