Ensure minting contract handles all of CIP25

[samuelWilliams99]

Specifically in relation for splitting strings into arrays for fields like images

[KindaSloth]

In general, the Mint collection contract seems to handle well the CIP25 docs, just two things that I want to bring up that maybe would be good to add:

• As I can see we're using version 2 of CIP25, but it doesn't seem that we're specifying this on the metadata.
• In the case of having multiple images would be good to have an option to pass an array of strings instead of just a string.

Both of these things maybe should require some changes in the CTL library, since we don't have the option to pass the version of the CIP25 metadata in the Cip25MetadataEntry datatype for example.