[predicates] Simplify specified_etype_implements

[web/views] Fix `has_editable_relation` predicate wrt inlined relations Prevents the "modify" action from being shown when there is nothing to edit.

[web/views] avoid propagation of NoSelectableObject in some case of inlined relations / permissions When selecting an inlined creation form, we should catch the NoSelectable exception that will be raised if the user cannot add entities of the target type (this is not and cannot be verified earlier) or if some other custom selector prevents the form from being selected. Closes #6510921

[server/test] bit of PEP8

[migration] don't attempt to carry over values when renaming a computed relation Without the fix in migractions.py, the introduced test crashes with an operational error because of an attempt to write to a non-existing relation table (computed relations are not materialized). Closes #6304946

consider .do_fti flag in index_entity method as this method may be used from outsite the class (eg in UpdateFTIHook), this is the proper way to consider it anyway. Closes #6206636

Added tag 3.19.13, debian/3.19.13-1, centos/3.19.13-1 for changeset f933a38d7ab5

[pkg] 3.19.13

[migration/3.21] add support for sqlserver Closes #7173702

moved_entities.extid may not be NULL