this is not used and cause a SyntaxWarning

page templates unicode resolver already takes care of coercing when
needed and this is directly compatible with python2 and python3
Co-authored-by: Kazuhiko SHIOZAKI <kazuhiko@nexedi.com>

This only works on python2

for same reason as the xhtml_style version, there is no problem with
having more than one listbox, see d2dedca3 (core: remove useless log
in Base_callDialogMethod, 2020-07-03)

See merge request nexedi/erp5!1932

Use same label as the action, "Preview"

These scripts take time to run, so restrict them to Manager users.

See merge request nexedi/erp5!1928

See merge request !1915

  The render is useful to preview content after edit while doing a gadget or on other contexts.

  Since corportate identity has erp5_web as dependency, it cause no harm to move.

See merge request nexedi/erp5!1919

   * const is handled as enum with a single value automatically
   * patch ensureArraySize to not modify the user input, let the user safely slice by himself.
   * Reorganise patches so it is grouped by prototype

Improvements compared to the previous implementation:
- avoid looking up the user document again, when the PAS plugin already did
  that job
- make it possible to call a single script when multiple sources of groups
  are based on the same documents, avoiding iterating unnecessarily on
  those same documents multiple times
- avoid repeating the same membership value (ex: when a user has multiple
  assignments with a common membership subset)
- avoid resolving the same relation more than once
- do not go from document value to relative URL only to go from relative
  URL back to document value at the next step
- move security group id extraction to unrestricted python, as the security
  overhead was taking a large amount of time
In a security setup with 8 scripts (all Assignment-based), 6 base
categories, and 4 Assignments (all valid), this implementation is 10 times
faster at producing the same group id set as the previous one.

See merge request nexedi/erp5!1918

   This prevents loose data and wrong edits.

   XXX update description on a squash to explain better.