CK Segment type 5

[dahlend]

Implement CK type 5.

https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/ck.html#Data%20Type%205

This follows the same design style that ESA used for the SPK file types they developed.

<rant>
Each of these sub-types do not appear to add any value beyond the previously existing formats, significantly add complexity, and in my opinion should never have existed. Type 6 immediately negates the entire argument of type 5, as type 5 was supposed to "prevent the proliferation" of types, and type 6 is an extension to type 5.
I would love for someone to provide me with a concrete example of motivation for the existence of these types. The only possible reason I can imagine is that it may very slightly reduce the size of a 2 mb file.
</rant>