How to search and replace carriage returns and tabs in Pages (version 8, 2019)
Solution:
This is pretty simple, but it was hard to find so here goes:
In the find or replace window you can use \n to find a carriage return (because \n = new line) or \t for a tab. It gets a little confused if you search for a single return and replace with a double return, but thankfully not the other way around. Hope this helps!
MacBook, OS X 10.11