ref-manual, dev-manual: Updated buildhistory figure

Fixes [YOCTO #5303]

Updated the figure to include a new folder named image-files.
Also changed the folder build-id to a file.

(From yocto-docs rev: eb6491858eabca3ce08ac1e4218b73e1ea7c893c)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>