* wc-api: Add user meta for UI preferences
This adds wc-api code to store UI preferences and provides one example
of updating the revenue table to save column preferences.
* wc-api user: fix returns of operations to arrays
Before, a function was returning undefined when the resourceNames didn't
include what we wanted for the user operations. This was causing some
console errors.
* ReportTable: use columnPrefsKey
This uses `columnPrefsKey` for the user preferences key instead of some
erroneously hard-coded values.
* Fix formatting/comments
These are a couple of small formatting and comment fixes.
* Replace woocommerce_meta_ prefix with wc_admin_
This changes the prefix for the meta fields for the `woocommerce_meta`
user meta array to be `wc_admin_` which better hints at the purpose of
these settings.
Kevin Killingsworth