Check if mod is published in CKAN triggers

[HebaruSan]

Problem

CKAN is receiving mod indexing requests for unpublished mods, which are then updated at publish. KSP-CKAN/NetKAN#7896:

Unpublished mods aren't supposed to be revealed to the world in any way, and CKAN's validation checks won't work until publish.

Cause

In #231 a notify_ckan call in create_mod was changed to send_to_ckan. notify_ckan did not make sense because it only works for mods that are already indexed. However, send_to_ckan still doesn't make sense because a mod at this point is not published, and all other usages of this function check mod.published. create_mod as currently written cannot validly trigger any CKAN events. However, in principle it is possible that at some point in the future create_mod might also set a mod as published, if such a change was worked on.

Changes

Now notify_ckan and send_to_ckan themselves check both mod.ckan and mod.published internally and only send triggers if both are true, so it will be safe to call either one whenever we want. NetKAN pull requests will now be submitted at publish instead of creation. The code calling these functions no longer checks either of these properties.

[DasSkelett]

Good solution. Thanks!