Revisit Sequence Templates arguments reformattting

[cartermak]

Checked for duplicates

No - I haven't checked

Alternatives considered

No - I haven't considered

Related problems

Right now, the arguments and computed attributes that get passed to sequence template expansion are all stringified:

https://github.com/NASA-AMMOS/aerie/blob/03df8fd53f63aba2a41430468fe4f06018b33269/sequencing-server/src/lib/mustache/util/activity.ts#L4-L20

This makes it impossible to, e.g., iterate over arrays/objects.

Describe the feature request

Remove this and, if some amount of stringification is necessary, make it smarter so as to not stringify arrays/objects.