classes: Update to use corrected bb.utils.explode_dep_versions2 API

classes: Update to use corrected bb.utils.explode_dep_versions2 API

The bb.utils.explode_dep_versions function has issues where dependency information
can be lost. The API doesn't support maintaining the correct information so this
changes to use a new function which correctly handles the data.

This patch also fixes various points in the code to ensure that we do not have any
duplicates in things that use explode_dep_versions.

A new sanity test to test the contents of the R* variables is also added.

[Some changes from Mark Hatle <mark.hatle@windriver.com>]

(From OE-Core rev: 16a892431d0c0d03f8b561b92909cf2f11af4918)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>