Do not access form submission REQUEST from the listbox list method,
as it is rendered asynchronously in ERP5JS

This reverts commit 35b2c024.

Allow edition in the new UI

This make everything slow as hell and prevent to quickly save.

Example: <h2 class="foo">bar</h2> => <h3 class="foo">bar</h3>

erp5_web_renderjs_ui: keep previous focus color

This reverts commit a87db49b.

Stop using ck_editor in read_only to display HTML.

This allows to get rid of the ck_editor iframe, allowing a faster load and removing the iframe scroll.
The maximise button is no more needed in such case.

It also removes all ck_editor links handling: links can be open in another browser tab now.

This changes impacts both xhtml style and erp5js.

This gadget take an HTML string as parameter.

It first cleans it up (with hardcoded behaviour currently) by dropping unknown tag elements, unknown/unsafe tag attributes.
It is another protection layer on top of asStrippedHTML inside ERP5.

Then, it displays the output HTML and style it with an hardcoded set of rules.

a928abd2 (web_renderjs_ui: use lxml to extract data-i18n messages, 2020-12-14)
was an old version of the patch that was pushed accidentally. This applies
the missing bits.

This is already working for multi-column conditions (among other malformed
values), but in the monocolumn case the type-check treats None in the same
branch as sequences, which cause the error:
  TypeError: 'NoneType' object is not iterable
As the condition is already covered for multi-column case, put this test
in the monocolumn codepath.

form_discussion_view embeds an editor, but it did not expose notifySubmit
method to child gadgets. Because using Ctrl+S in the editor calls
notifySubmit on parent gadget, Ctrl+S was causing a page crash.

Expose such a method that would submit a comment when called.

The previous regular expression based approach sometimes could not extract
message properly. Using xml parser simplify code and fix several messages
that were not extracted properly, like messages containing ", [] or {}

This also fix some problems when looking for messages sources:
  - archived web pages were sometimes used instead of published ones
  - messages from gadgets implemented as page templates/OFS files were not
    extracted.

A few more unit tests for the scripts involved in this process are added.

Fixes the handling of:
- non-sequence dependency_value
- incorrect dependency_value length
- None in dependency_value
- None in dependency_value items

So more sequence types are accepted by _getExecutableMessageSet.

See nexedi/erp5@6c4f7600