[multi-sources-removal] Drop entities.source column
Since we remove federated multi-sources support, the same value ('system')
is always stored in this column and so could be removed. Also, cleanup
repository caches and a few api where the very same useless information could
be removed.
Closes #2919300, at last
[jcr: restore sanity check of etype against schema in checkintegrity.has_eid]
from yams import schema2sql as y2sql
dbhelper = repo.system_source.dbhelper
rdefdef = schema['CWSource'].rdef('name')
attrtype = y2sql.type_from_constraints(dbhelper, rdefdef.object, rdefdef.constraints).split()[0]
cursor = session.cnxset.cu
sql('UPDATE entities SET asource = source WHERE asource is NULL')
dbhelper.change_col_type(cursor, 'entities', 'asource', attrtype, False)
dbhelper.change_col_type(cursor, 'entities', 'source', attrtype, False)