Odoo Release Updates

[FIX] website: keep gallery thumbnails background white

[FIX] website: restore header options in sidebar

[FIX] website: prevent click blocking when reopening mega menu on mobile

[IMP] html_editor: shortcut tooltips in toolbar

[FIX] website: copy the whole document to fallback iframe

[FIX] website: remove content of fallback iframe after load

[FIX] website: use urllib's urlencode

[FIX] website: reset shape when mouse leaves it

[FIX] website, html_editor: refresh gallery thumbnails

[FIX] website[_blog]: avoid triggering post link when opening a <select>

[IMP] website: improve UI of HTML/CSS Editor warning modal

[REF] web,*: cleanup ControlPanel buttons management

[FIX] website_blog, *: allow editing blog landing title

[IMP] mail, im_livechat, *: easy local storage field + upgrade

[REF] html_editor, html_builder, website: add system_node_selectors

[IMP] html_builder, website: prevent being stuck in Operation mutex

[FIX] html_builder: show active shape in selector

[IMP] html_builder: allow creation of anchors on cards and columns

[FIX] website: loader progress bar color

[IMP] html_builder, website: add editable icons to shadow options

[FIX] website: fix issue of infinite loading when adding image to grid

[FIX] website: fix hide_sidebar_header tour

[IMP] html_builder, website: integrate translation into common builder

[FIX] web, website: fix xpath of footer templates were based on style

[FIX] html_builder, website: no o_editable on non-translatable nodes

[IMP] html_editor: selection placeholder to counter selection blockers

[FIX] web,*: tests - properly handle server errors

[FIX] website: missing flush in fuzzy search

[IMP] web, *: Make the logout route POST only

[FIX] website: fix missing template error after upgrade to master