Add __fish_seen_argument_from wrapper

There are a million existing ways of skinning this cat, but it's a good parallel
to `__fish_seen_argument` to have, in a similar vein to
`__fish_seen_subcommand_from`.

share/functions/__fish_seen_argument_from.fish

@@ -0,0 +1,8 @@
+function __fish_seen_argument_from
+    for arg in $argv
+        if __fish_seen_argument -- $arg
+            return 0
+        end
+    end
+    return 1
+end