Character name max length increase by 2. (cmss13-devs#5358)

# About the pull request
Bumping the max name length by two. I've seen a few people who drop the
quotations on their nickname to save characters to fit the name they
want. This would help allow them to have quotations on their nick again.

# Explain why it's good for the game

Letting people have the names they want without having to gimmick the
quotation character count.


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
qol: increased name character limit by two.
/:cl:

code/__DEFINES/text.dm

@@ -23,4 +23,4 @@
 #define MAX_EMOTE_LEN 256
 #define MAX_PAPER_MESSAGE_LEN 3072
 #define MAX_BOOK_MESSAGE_LEN 9216
-#define MAX_NAME_LEN 26
+#define MAX_NAME_LEN 28