Add new caching functions named `wp_cache_add_multiple`, `wp_cache_set_multiple` and `wp_cache_delete_multiple`. All of these functions allow for an array of data to be passed, so that multiple cache objects can be created / edited / deleted in a single function call. This follows on from [47938] where the `wp_cache_get_multiple` function was introduced and allowed for multiple cache objects to be received in one call.
Props: spacedmonkey, tillkruess, adamsilverstein, flixos90, mitogh, pbearne.
Fixes: #54574.
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git-svn-id: http://core.svn.wordpress.org/trunk@52289 1a063a9b-81f0-0310-95a4-ce76da25c4cd
