Links in Setting pages to open in new window

[theadityajain]

Some links in the Setting Pages (General, Discussion, Permalink) pages open in same window, which sometime can be awful.
While the users can press cmd/ctrl + click and click the link to open it in new tab but If the user does not open the link in new window, options (which are not saved) will be lost and one have to go through them again.
Also links in the Edit Profile page and all the links in the help tab open in new window except a few.(so it is possible that users may just click it thinking them to alike other links which open in new window)
So a consistency will be there and ux can be a little better.

Related: #14099

Related: #20839