Save statically once the media fields

[MaximeCulea]

In each helper, we duplicate code and reuse the same "helper" to get possible ACF media fields to work with.

So we could move and refactor recursive_get_post_media_fields into admin/main to be triggered on acf_save_post action.

This will cause to check fields once and save somewhere as static to faster/easier reuse into helpers.

@herewithme your thought ?

[herewithme]

@MaximeCulea 100% agree.
But I'm not sure that we should invest time on the current format because ACF should be totally outsourced in an addon.

[MaximeCulea]

Let's do things step by step ;)
We should have done it here #51 (comment) :p
Anyway I created an issue #68 to focus on this refactoring.

[herewithme]

Yes, complementary subject.