Workers created from Blobs inherit their CSP. Now we inherit the CSP and
set the correct base API url. The base API url should be used when
determining the
report-uri endpoint. Otherwise, the blob URL would be used as a base,
which is invalid and the report wouldn't be sent.
Also create a helper method to concatenate two optionals of CSPList,
which was used in several places.
Part of #4577
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
Most tests were only being run for layout-2013, not for layout-2020.
This wasn't great since layout-2020 is now the default.
So this patch unifies the lists of included tests for both layouts.
For layout-2013 this implies adding css/css-content/, css/css-logical/
and css/css-masking/clip/.
For layout-2020 this implies adding several additional css tests, and
also tests like dom/, js/, html/, etc.
