Logging Improvements (#3652)

# About the pull request
Makes admin deadchat logs clearer
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# Explain why it's good for the game
Logs being confusing isn't good
# 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:
admin: Improves logging for admin deadchat.
admin: Adds logging for xeno evolution.
/:cl:

code/modules/admin/verbs/deadsay.dm

@@ -23,7 +23,7 @@
 	stafftype = "[admin_holder.rank]"
 
 	msg = strip_html(msg)
-	log_admin("[key_name(src)] : [msg]")
+	log_admin("DEAD: [key_name(src)] : [msg]")
 
 	if (!msg)
 		return

code/modules/mob/living/carbon/xenomorph/Evolution.dm

@@ -140,6 +140,7 @@
 		if(3)
 			hive.tier_3_xenos |= new_xeno
 
+	log_game("EVOLVE: [key_name(src)] evolved into [new_xeno].")
 	if(mind)
 		mind.transfer_to(new_xeno)
 	else
@@ -327,6 +328,7 @@
 			qdel(new_xeno)
 		return
 
+	log_game("EVOLVE: [key_name(src)] de-evolved into [new_xeno].")
 	if(mind)
 		mind.transfer_to(new_xeno)
 	else