What is the name, if they exist, of PCB mountable 120 AC outlet connectors?
If you don't mind using a power cord, I highly recommend using a PCB-mount IEC connector instead. These are very common and readily available.



If you absolutely must have a device that plugs directly into the wall, I recommend building your Wifi extender into an enclosure with an integrated mains plug:



Individual PCB-mount mains contacts do exist, but are fairly uncommon and difficult to source. I recommend using one of the above options instead.

EDIT: It looks like Heyco (a company owned by PennEngineering) makes PCB-mount mains blades:

https://www.heyco.com/Power_Components/pdf/PCB-Contacts.pdf