Select2boxes multiple widget does not work properly with paragraphs

Problem

The problem is that when you are using a taxonomy term reference field with select2boxes multiple values widget inside a paragraph field having multiple values, when you add another paragraph item, the new taxonomy term reference field added will take the values from the previous one.

Steps to reproduce

• Install the paragraphs contrib module
• Create a new paragraph bundle and add a new taxonomy term reference field to it, with multiple values and the widget "Select2 boxes (Multiple values)"
• Add the newly created paragraph to a content type as field and enable the unlimited values option for it.
• When creating a new content, add some values to the previously created field and then add another paragraph item. The second paragraphs item field added should have the same values as the previous field.

Solution

For this we need to change the keys of the "initValues" array by adding the parent field to the identifier so that the jQuery selector will differentiate the fields.