Add the possibility to share handlebars template between processes

[freddidierRTE]

Add in state defintion in config.json another field : templateFromAnotherProcess

Example :

templateFromAnotherProcess : 
  {
     processId: myProcess
     templateName : "myTemplateFile.handlebars"
     version: 1
  }

When this field is present , the front shall use the template from the specify process instead of the templte define in templateName

Implementation : The choice of the template shall be done in TemplateRenderingComponent.ts