overview-manual: convert analysis-for-package-splitting.png to svg

- Convert the png file to an SVG file
- Add the UNPACKDIR reference.
- Remove ${PR} from WORKDIR value, after cc83e4548465 ("bitbake.conf:
  Drop PE and PR from WORKDIR and STAMP") on OE-Core.
- Change S value to BP (equal to ${BPN}-${PV}, but more accurate).

(From yocto-docs rev: 6fd6af3ea9e556e481cc3c0358c0357b6060798f)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/overview-manual/concepts.rst

@@ -861,7 +861,7 @@ Package Splitting
 After source code is configured, compiled, and staged, the build system
 analyzes the results and splits the output into packages:
 
-.. image:: figures/analysis-for-package-splitting.png
+.. image:: svg/analysis-for-package-splitting.*
    :width: 100%
 
 The :ref:`ref-tasks-package` and