See merge request nexedi/erp5!1719

https://lab.nexedi.com/nexedi/erp5/blob/bb7d107124e96a6176f56226d3093d8845c3949d/product/Formulator/Form.py#L228

See merge request nexedi/erp5!1718

context is actually a web section

replaces nexedi/erp5!1691 

See merge request nexedi/erp5!1709

See merge request nexedi/erp5!1715

There is no good reason to prevent editing in cancelled state and
it can be needed, for example to remove a cancelled payment
transaction from a payment transaction group.

Unlike StringIO.StringIO().tell() and open().tell(), which all return
int, io.BytesIO().tell() returns long. Because io.BytesIO is used when
uploading files on Zope4, this cause PropertySheetValidity errors when
checking consistency, because Data.size property is expected to be int.

Checks that created document types match constraints

Previously, we were using an encoded string, which in practice worked,
but with python3, WSGI server will encode as latin1 (because WSGI is
latin1) and already with Zope4 on python2 we have issues with testing,
as functional testing fake WSGI server only accepts ascii headers [1]

1: https://github.com/zopefoundation/Zope/blob/cddecf7e/src/Testing/ZopeTestCase/functional.py#L125-L126

Since Zope 4, the `standard_error_message` is rendered in the context
of REQUEST['PUBLISHED'], which in case of publishing a skin (page
template or script) in the context of a document is is the skin itself,
but for error rendering in case of erp5_web Web Site or Web Section,
we expect standard_error_message_template to always be rendered in the
context of the document, that's why we use REQUEST.PARENTS[0] as context.

REQUEST.PUBLISHED = <PythonScript at /erp5/script used for /erp5/module/document>
REQUEST.PARENTS [<Document>, <Module>, <ERP5Site>, ...]

This is different from the total of durations of test result lines
because they are executed in parralel on different testnodes. The
actual duration is just the difference between start and stop, so
that we don't have to calculate.

This makes it easier to understand the duration in minutes and hours

Ran https://github.com/python/cpython/blob/3.7/Lib/lib2to3/fixes/fix_asserts.py after adding the missing methods (assertRegex and assertRaisesRegex) on ERP5TypeTestCase.

Also ran a custom fixer rewriting
 
```py
self.assertTrue(a in b)
```

into

```py
self.assertIn(a, b)
```

See merge request !1708

Prepare for https://github.com/zopefoundation/Zope/pull/1075 ( Zope 4.8.7 )

See merge request !1707

and fix some missing cache

See merge request nexedi/erp5!1674

automaticLayout can not be used with firefox 68 (the browser from test
nodes) because it lacks support for ResizeObserver

triggered manually with "Format Document" of "Format Selection"
actions

This enables usage of @ in quick pick to search for symbols and make
sticky scroll show the current context

   Probably there are missing files but it is a start.

With tweaks to support firefox 68 from test nodes:
 - build with babel, see jerome/monaco-editor-erp5@cf10f2d5
 - special handling of ResizeObserver that does not exist in Firefox
   68: it is used only for automaticLayout, which is not strictly
   needed. So this feature will not work for firefox 68.

Enable sticky scroll

Set caching manager to must_revalidate_http_cache