[repository] set .eid on eschema when schema is loaded from the filesystem
enforcing the contract that a repository's schema should have .eid attribute of
entity schema set to the eid of the entity used to serialize them in the db.
Before this cset, this was not true during tests or for some c-c commands where
'quick_start' is set (eg db-restore, i18ncube...).
The change in server __init__ makes this assumption true during instance
creation: the serializing code was actually setting eid on schema object, but a
reference to a previously built schema was given instead of the one for the
latest created repository.
Closes #10450092
Metadata
--------
.. index::
schema: meta-data;
schema: eid; creation_date; modification_data; cwuri
schema: created_by; owned_by; is; is_instance;
Each entity type in |cubicweb| has at least the following meta-data attributes and relations:
`eid`
entity's identifier which is unique in an instance. We usually call this identifier `eid` for historical reason.
`creation_date`
Date and time of the creation of the entity.
`modification_date`
Date and time of the latest modification of an entity.
`cwuri`
Reference URL of the entity, which is not expected to change.
`created_by`
Relation to the :ref:`users <CWUser>` who has created the entity
`owned_by`
Relation to :ref:`users <CWUser>` whom the entity belongs; usually the creator but not
necessary, and it could have multiple owners notably for permission control
`is`
Relation to the :ref:`entity type <CWEType>` of which type the entity is.
`is_instance`
Relation to the :ref:`entity types <CWEType>` of which type the
entity is an instance of.