feat(connect): filepath completion #38959

This is a stop-gap; the next step is for :connect to show a menu of
known peers (and perhaps also any files in CWD that look like sockets).

(cherry picked from commit 6f015cdcdf)

src/nvim/ex_cmds.lua

@@ -632,7 +632,7 @@ M.cmds = {
   },
   {
     command = 'connect',
-    flags = bit.bor(BANG, WORD1, NOTRLCOM, NEEDARG),
+    flags = bit.bor(BANG, FILE1, NOTRLCOM, NEEDARG),
     addr_type = 'ADDR_NONE',
     func = 'ex_connect',
   },