Implement From trait for conversions between Clade, TelomereSeq and Seq

[lavafroth]

Changes

• Convert clades into enum
• Use the strum crate for easy operations between the Clade enum and strings
• Do not use heap allocate inner slice of a Seq
• Implement From trait to convert Clade into Seq
• Implement From trait to convert Clade into TelomereSeq
• Removes redundant length field for TelomereSeq, now accessed through the len method of the seq field
• Do not panic when parsing string as clade and getting the respective telomere sequence, return a result instead. Can aid with Make errors better & more informative #7

[Euphrasiologist]

Thanks for this - I will get around to looking at this. Just writing up tidk as a paper at the moment, so on a code freeze for a bit. I also need to think whether we should introduce more crates for this!

[lavafroth]

Sure thing! Maybe we can have a separate branch to work on while the main branch code stays frozen?