message: Add change note
diff: * Fix corruption caused by `swap_rows()` and `move_column()` operations applied
  to a StringEnumColumn. Currently unused by bindings.
  PR [#2780](https://github.com/realm/realm-core/pull/2780).
  +* Fix case insensitive contains query for null strings not returning all results and
  + Fix case insensitive equals query for null strings returning nothing when null strings exist.
  + PR [#2871](https://github.com/realm/realm-core/pull/2871).
  ### Breaking changes
  