Commands other than `open` are slowed down by GUI dependencies

Among the commands for the larvatagger.sh and larvatagger.jl scripts, only open requires the GUI dependencies. The other commands, including import, train, predict, do not need packages such as Makie.

Problem: Makie takes a while to load (and also to reload).

Proposal: Find a way to conditionally load JSServe and Makie/WGLMakie.

added Speed/reactivity label

mentioned in commit 51aa6f59

Release 0.13 cuts down to half the start time of the open command. DocOpt is likely the cause of the remaining half and should be replaced for all cases (open and other commands).

As there is another issue for DocOpt (#59), I close this one as fixed by release 0.13.

closed