Update clip-path-shape-003.html and clip-path-shape-004.html because
1. Per SVG2 spec, we don't accept comma among commands, so I remove them.
2. Basically, these two tests want to test the result of `shape()`
should be identical to the result of `path()`. However, I noticed the
original tests which put a `clip-path:path()` with `position:absolutely`
may have a fuzzy result if the path has some curves there. This may be
caused by anti-alias together with absoultely positioned element
(note: perhaps there are some floating point calculation in layout for
this, so the final rendering coordinates may have some fractions).
Therefore, I drop the absolutely positioned element, and just test
that if the result of `shape()` is identical to the result of `path()`.
Also, add two more tests for different reference-boxes together with
the usage of `shape()` (to make sure we resolve percentage values properly).
Differential Revision: https://phabricator.services.mozilla.com/D202884