Refactors menubar creation to avoid a null parent window during
construction; moves search options to the more traditional edit
menu; creates and exclusive action group for bytes per row
Fixes#5177 in part
Now that WindowServer broadcasts the system theme using an anonymous
file, we need clients to pledge "recvfd" so they can receive it.
Some programs keep the "shared_buffer" pledge since it's still used for
a handful of things.
