Create basic interface for choosing a published code list

[TomasEng]

For components that use code lists, the layout editor should support published code lists. We should add a button to the interface that lets the user specify a published code list.

Definition of done

• When the user edits a component that uses a code list in the layout editor, and no code list is selected, there is a button that lets the user choose a published code list
• When the user clicks the button, the user is asked to specify the name of the code list and what version to use
• The input field for version regards any whole number and _latest as valid values
• The settings described above are saved when the user clicks a "Save" button
• When a published code list is selected:
  • The name and version are visible in the interface
  • There is a button that lets the user delete the reference

With this criteria in place, all CRUD operations for code list references are supported. This includes updating, although it must be done by deleting the current reference and creating a new one. Creating requires the user to know the code list name and version to use. There will be other issues covering the improvement of this.

Out of scope

• Editing code list references when already set
• Checkbox for latest version
• Lists of available code list names and versions to choose from