[source/native] refactor eid generation code
This set of related methods clutters the native source API.
It will be better served with a dedicated eid genrator object.
Related to #3526594.
[jcr: allocate the eid generator in __init__]
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
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"""%(distname)s schema"""