See merge request !696

This will support buildout extension to download from gitlab API with
authentication.

The code has already been refactored a bit to be able to pass a
download instance to SoftwareReleaseSchema, for now to instanciate only
one Download but in the future this might be extended to pass some
configuration to the Download instance.

The performance was much worse.

Workflow state was not the correct one.

See 76edda30

This partially reverts commit 14c39681.

There is no need for custom the actions, as on slapos_panel fast input is
used instead.

Keep for now the older state name for ensure consistency with the current
usage.

   This was replaced on the panel so, no need to have it on workflow action. This may reduce the delta on the workflow itself.

   For sure, we won't calculate worklist from this form

    This workflow isn't used any more since the re-implementation.

   This prevents produce inconsistent objects whenever system evolve.

  New string to translate
  int to bool change on XML

  DeprecationWarning: <Workflow at instance_slap_interface_workflow>: Script calling Instance_checkConsistency instead of script_Instance_checkConsistency

   Provide all common options as a method, so it is easy to understand security.

moved from erp5 SR test suite

See merge request nexedi/slapos.core!705

adjusted to use findFreeTCPPortRange and fix typing / formatting errors

  Ensure to convert the text values to a safer output that will be compatible with XML 1.0.
  See: https://www.w3.org/TR/REC-xml/#NT-Char

   Try to guarantee that data is consistent and wont fail later on
   while been converted to XML with special attention to non-XML
   compatibles characters, like backspace.

   Include constraint to ensure title is XML compatible on Software
   Instance, Instance Tree and Slave Instance. (Not required for Compute
   Node as far as I checked).

   Copy text_content (parameter), sla_xml constraints from
   Software Instance to Instance Tree and Slave Instance.

   Copy connection_xml constraint from Software to Slave Instance for
   consistency.

   Add more tests to ensure that an Instance cannot be created if data
   is invalid, or not XML compatible.

   Add utility scripts to validate XML and XML Marshaller compatibility