[Feature] Encourage .netkan properties, discourage .ckan properties

[HebaruSan]

Problem

When people generate a netkan with the metadata-webtool, the tendency is to fill in every field that's available (an admirable conscientious atittude), but we present a lot of fields that shouldn't be used or aren't needed. This makes for slightly more clean-up work during review.

Some recent examples:

• Add ASETProps NetKAN#9564
• Add ASETAvionics NetKAN#9566
• Add ASETAgency NetKAN#9568

Suggestions

Consider hiding properties that are determined programmatically during inflation:

• version
• ksp_version, ksp_version_min, ksp_version_max
• download
• name, abstract, resources (for SpaceDock)
• release_status
• resources.ci
• resources.x_screenshot
• resources.repository
• resources.bugtracker
• resources.homepage (for SpaceDock)
• resources.spacedock
• resources.license

This would more often produce metadata that's ready to merge.