On profile edit screen, update 'This field can be seen by' dynamically

[boonebgorges]

From a user report (​https://buddypress.trac.wordpress.org/ticket/4233#comment:13):

If you click on the "Change"-link to change the visibility of the chosen profile field, the selected visiblity doesn't refresh. For example if it's "This field can be seen by: Anyone" and you select in the box "Logged in Users" it's still "This field can be seen by: Anyone". However, if you save the settings your changes will be carried over.

This should just take a line or two of JS.

[boonebgorges]

As I started to build this, it occurred to me that it's probably going to result in some confusion if implemented. That's because, when you switch the radio button setting, *it is not actually the case* that the visibility level has been changed - you have to submit the form to save the change. So it would be misleading to say so.

I guess the solution for this is to actually change it using AJAX. But this is beyond the scope of what I want to do for this dev cycle.

[sooskriszta]

Perhaps we should just make it clearer that Privacy setting would be saved only upon hitting the Save Profile button?

[boonebgorges]

Perhaps we should just make it clearer that Privacy setting would be saved only upon hitting the Save Profile button?

I believe we added functionality that warns the user before leaving the edit screen with unsaved changes. Can you check that?

[boonebgorges]

Closing in favor of #5896, which has some code attached.