[schema] mark CWDataImport as an internal type. Closes #3025536

[pkg] remove deprecated dependency on pysqlite2

Fix two crashes in db-check (closes #3024964) Also improves various debugging messages.

[rql rewrite] may_be_shared_with should consider relation's scope (closes #3024730) When a relation's scope is not the current statement, it must not be shared (instead of comparing the statement).

[rql rewrite] fix may_be_shared_with method so that it actually considers all variable infos and not only the first one

[schema/security] add __hash__ to rql expression. Closes #3013535 This is required so that when some rql expression participate to a dictionary key, only the expression is considered (consistent with comparison). This behaviour is expected in security at least, see the related bug for instance. This scramble msplanner unit tests a bit.

[rql rewrite] move some code from querier to rqlrewrite where it makes more sense. Also, make some minor cleanup/refactoring on the way and try to enhance docstrings. Relates to #3013535

Do not compute actions list in TableLayout view when display_actions attribute is unset Closes #3007281

Use the list of cubes from the filesystem when reading the schema from the filesystem Closes #3007259

[migration] when adding a cube, skip infered relations (closes #3005576) Skipped infered relations are recalculated later.