Add the option to search for the automatic messages of people joining a server

Every time a new member joins an automatic message is created (with green arrow), but there is no way to crtl+f find these messages and the moments people joined (or even for the confirmation that somebody joined). 

Having an option to search for them would quite a lot ease the task of looking through a busy server to find how many people have joined recently and who they were. 

These messages can be found as the first message ever "sent" by any member, but that requires knowing the name of a person that joined. There is no way to do the opposite and find the name of a person that recently joined by searching for the automatic message.

From what I see these messages can't be found by searching for any word they contain.