dialect/sql/schema: added support for ydb schema migrations#9

kprokopenko merged 2 commits intoydb-platform:ydb-developydb-platform/ent:ydb-developfrom

LostImagin4tion:LostImagin4tion/schema-migrations-supportLostImagin4tion/ent:LostImagin4tion/schema-migrations-supportCopy head branch name to clipboard