The word filter will now be less scared of double or trailing spaces (#62703)

It kept on tripping because the RegEx expression was malformed due to an absence of words in to_join_on_whitespace_splits, which caused it to filter out spaces that were at the beginning or at the end of a message, or if there was two spaces one by the other.

Also prevents people from sending a message that's only spaces in OOC, because that's a little silly.

code/modules/unit_tests/chat_filter.dm

@@ -50,6 +50,14 @@
 		BLOCKED_SHARED,
 	)
 
+	test_filter(
+		" This message has a space at the beginning, a  double space, and a space at the end, but it's fine! ",
+		null,
+		null,
+		null,
+		null,
+	)
+
 /datum/unit_test/chat_filter_sanity/proc/test_filter(
 	message,
 	blocked_word,