This patch fixes the remaining issues that were reported due to the logic engine
rework done in 3.4. We apologise for the disruptions these bugs have caused. The
rework being done is quite substantial and we've put some controls in place to make
reverting to old behaviour possible, but unfortunately some things still slip through.

* [:backend:`6007`] Fixed hidden fields not being sent to the Objects API when using the
  variable mapping (v2 configuration) configuration. Additionally, fixed other places
  where the "unsaved variables" where not being included in the evaluation scope for
  templates.
* [:backend:`6014`] Fixed components using overlapping (nested) keys with their parent
  component causing logic crashes.
* [:backend:`6001`] Fixed components inside layout components (fieldset, columns) having
  their value cleared despite having their visibility state managed through backend
  logic rules.
* [:backend:`5980`] Fixed components being listed in the form summary/overview despite
  being hidden through logic rules.