[IMP] test_themes, theme_*: adapt themes for new parallax structure

This commit adapts the themes to the new Parallax effect structure.
We now wrap the parallax element in another element with
"overflow: hidden" to avoid setting "overflow: hidden" on sections.
That was causing elements like the dropdown of the search bar to be cut
off and not fully visible.

task-4926420

closes odoo/design-themes#1114

Related: odoo/odoo#218296
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

theme_bewise/views/customizations.xml

@@ -14,7 +14,7 @@
         <div class="o_we_shape o_html_builder_Rainy_08_001"/>
     </xpath>
     <!-- Remove the background image for parallax -->
-    <xpath expr="//span[hasclass('s_parallax_bg')]" position="replace"/>
+    <xpath expr="//span[hasclass('s_parallax_bg_wrap')]" position="replace"/>
     <!-- Title -->
     <xpath expr="//h1" position="replace" mode="inner">
         Always at the top