Add support for premium app integrations

Co-authored-by: Danny <1695103+Rapptz@users.noreply.github.com>
Co-authored-by: Lucas Hardt <lucas.hardt@fu-berlin.de>
Co-authored-by: Andrin S. <65789180+Puncher1@users.noreply.github.com>

discord/flags.py

@@ -60,6 +60,7 @@ __all__ = (
     'MemberFlags',
     'AttachmentFlags',
     'RoleFlags',
+    'SKUFlags',
 )
 
 BF = TypeVar('BF', bound='BaseFlags')
@@ -1971,3 +1972,76 @@ class RoleFlags(BaseFlags):
     def in_prompt(self):
         """:class:`bool`: Returns ``True`` if the role can be selected by members in an onboarding prompt."""
         return 1 << 0
+
+
+@fill_with_flags()
+class SKUFlags(BaseFlags):
+    r"""Wraps up the Discord SKU flags
+
+    .. versionadded:: 2.4
+
+    .. container:: operations
+
+        .. describe:: x == y
+
+            Checks if two SKUFlags are equal.
+
+        .. describe:: x != y
+
+            Checks if two SKUFlags are not equal.
+
+        .. describe:: x | y, x |= y
+
+            Returns a SKUFlags instance with all enabled flags from
+            both x and y.
+
+        .. describe:: x & y, x &= y
+
+            Returns a SKUFlags instance with only flags enabled on
+            both x and y.
+
+        .. describe:: x ^ y, x ^= y
+
+            Returns a SKUFlags instance with only flags enabled on
+            only one of x or y, not on both.
+
+        .. describe:: ~x
+
+            Returns a SKUFlags instance with all flags inverted from x.
+
+        .. describe:: hash(x)
+
+            Return the flag's hash.
+
+        .. describe:: iter(x)
+
+            Returns an iterator of ``(name, value)`` pairs. This allows it
+            to be, for example, constructed as a dict or a list of pairs.
+            Note that aliases are not shown.
+
+        .. describe:: bool(b)
+
+            Returns whether any flag is set to ``True``.
+
+
+    Attributes
+    -----------
+    value: :class:`int`
+        The raw value. You should query flags via the properties
+        rather than using this raw value.
+    """
+
+    @flag_value
+    def available(self):
+        """:class:`bool`: Returns ``True`` if the SKU is available for purchase."""
+        return 1 << 2
+
+    @flag_value
+    def guild_subscription(self):
+        """:class:`bool`: Returns ``True`` if the SKU is a guild subscription."""
+        return 1 << 7
+
+    @flag_value
+    def user_subscription(self):
+        """:class:`bool`: Returns ``True`` if the SKU is a user subscription."""
+        return 1 << 8