presence: Use the narrow user cache.

These two endpoints make up ~85% of requests to Zulip servers; since
presence is also a performance-critical endpoint, having them share
the same cache increases how hot it stays in memcached, in addition to
making the presence endpoint faster.

This comes at the very slightly cost of one extra field.  Checks
for the `is_bot` column are switched to the equivalent `bot_type`
check, since the columns are slightly duplicative, and we can get away
with only checking bot_type.

zerver/models/users.py

@@ -964,6 +964,7 @@ def get_user_profile_narrow_by_id(user_profile_id: int) -> UserProfile:
             "id",
             "bot_type",
             "is_active",
+            "presence_enabled",
             "rate_limits",
             "role",
             "recipient_id",