Protect MultiValueField field

According to the wiki, https://documentation.magnolia-cms.com/display/DOCS61/Live+Copy+module

We have 3 levels of protecting to protect Livecopy content from changes of Master content:

• Full pages
  • liveCopyReferenceDropped=true property will be set to the node of page
• Single components
  • liveCopyReferenceDropped=true property will be set to the node of component
• Single fields
  • Didn't mention in the wiki, but propertiesToIgnore = [fieldNameProtected,...] will be set to the node of component
  • The term properties above represent for normal field whose value is stored in property of jcr; for a complex field, whose value may be stored in node. Then could the properties term here cover for both cases: property and node

For the special case MultiValueField (or MultiField in UI 6), we shouldn't allow to protect the child field, since they don't have distinct name in generally.

E.g: The compatibility MultiValueField contains a list of LinkFields will be stored in JCR as a property like: multiValueField = [uuidOfLinkTarget_1, uuidOfLinkTarget_2,...], hence we cannot extract name of each child field in this case.

AC:

• propertiesToIgnore: apply for both field value is node and is property
• Do not apply protect for child field of MultiValueField/MultiField, but only MultiValueField/MultiField
• Do not show protect icon for child field of MultiValueField/MultiField, but only MultiValueField/MultiField

MultiValue RichTextField: as expected

 MultiValue LinkField: as expected

 MultiValue Composite (RichTextField + LinkField): not as expected >> need to be improved