cubicweb-trackervcs #4439404 ensure the vcsinlude directive use the project's repo by default [validation pending]

the vcsinlude depends on a ".vcsrepository" attribute on the context entity (here, should be a Project). So in order to make it possible to use the 'vcsinclude' directive in the context of a Project'd description that defaults to the Project's Repository, must add this 'vcsrepository' attribute to the Project ORM entity.

done in1.2.0
load left0.000
closed by#bc8ddf0febd5 [entities] add a repository property on Project
patch[entities] add a repository property on Project [applied]