[V3 Mod/Modlog] prevent self-casing the bot + feedback for heirarchy (#…

…1777)

* prevent the bot from being a modlog target

* prevent heirarchy issues in mod

* modify this comparison to avoid more complex mocking of the guild object in mod test

* spelling

redbot/cogs/mod/mod.py

@@ -316,6 +316,9 @@ async def kick(self, ctx: commands.Context, user: discord.Member, *, reason: str
                 )
             )
             return
+        elif ctx.guild.me.top_role <= user.top_role or user == ctx.guild.owner:
+            await ctx.send(_("I cannot do that due to discord hierarchy rules"))
+            return
         audit_reason = get_audit_reason(author, reason)
         try:
             await guild.kick(user, reason=audit_reason)
@@ -369,6 +372,9 @@ async def ban(
                 )
             )
             return
+        elif ctx.guild.me.top_role <= user.top_role or user == ctx.guild.owner:
+            await ctx.send(_("I cannot do that due to discord hierarchy rules"))
+            return
 
         if days:
             if days.isdigit():

redbot/core/modlog.py

@@ -461,6 +461,9 @@ async def create_case(
     if not await case_type.is_enabled():
         return None
 
+    if user == bot.user:
+        return None
+
     next_case_number = int(await get_next_case_number(guild))
 
     case = Case(