Add message indicating custom attributes will not be copied to a new incident

[noah-schechter]

I think we should change "Copy this incident into another project. Note that restrictions and media that has been hidden from view (i.e., marked as hidden or removed) will not be copied." to "Copy this incident into another project. Note that custom attributes, restrictions, and media that has been hidden from view (i.e., marked as hidden or removed) will not be copied."

Also, what do 'restrictions' refer to here?

[milesmcc]

Custom attributes will be copied when it's possible to copy them

[milesmcc]

Restrictions refers to whether the incident is frozen

[milesmcc]

How about: Copy this incident into another project. Note that restrictions (i.e., whether the incident is hidden or frozen) and media that has been hidden from view (i.e., marked as hidden or removed) will not be copied. Attributes will be copied when possible.

[noah-schechter]

Custom attributes will be copied when it's possible to copy them

When dictates whether it's possible to copy a custom attribute?

[milesmcc]

There is a corresponding custom attribute in the new project with 1) the same name, and 2) the data "fits" (e.g., for multi-selects, all the provided options are available in the incoming attribute's values).