Rudder

So there is two part on that bug:

1/ Mapping editor <-> YAML

The first (this ticket) is that the canonization used to be done by rudder webapp and put in the XML. Now, if we want to have it in the yaml, we really need to expose a new field in the technique editor, variable name, which will be used in place of the automatically canonified field.

The UI will pre-fill the input with something sensible from name field. The variable name field must only accept chars in the [\alpha][\alphanum_]* range (ok for vb variable name, ok for cfengine canonification, ok for most lang function name, etc).

Then the mapping is:
- editor hidden field UUID maps to YAML id (optionnal) maps to xml NAME
- editor name maps to YAML description maps to xml DESCRIPTION
- editor variable name maps to YAML name maps to NOTHING in XML
- editor description maps to YAML documentation maps to XML LONGDESCRIPTION

2/ Migration

See #23555