Handle multiple game versions from Curse

[HebaruSan]

Background

Curse lets mod authors select multiple game versions (this list appears upon hovering the "+9" with the mouse):

This data appears in a versions property in the API:

https://api.cfwidget.com/project/283006

"versions":["1.2","1.2.1","1.2.2","1.3","1.3.1","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4"]

Problem

Currently Netkan ignores those values; instead, the single game version from the version property in the API is used, and any broader compatibility can only be set with a $vref or with overrides.

I think the quirks of the selection of the value of that property somehow caused KSP-CKAN/NetKAN#6622.

Changes

Now we parse the full game version list. This is done with by adding a new CurseFile.versions property and extending JsonConvertKSPVersion to support arrays.

If there are multiple game versions, we set ksp_version_min to the earliest and ksp_version_max to the latest. Otherwise the single game version is set to ksp_version, as before.

Fixes KSP-CKAN/NetKAN#6622 better than KSP-CKAN/NetKAN#6674 did (the latter can now be reverted).