Move various system functionality to system.py

src/pluralkit/errors.py

@@ -0,0 +1,36 @@
+class PluralKitError(Exception):
+    pass
+
+
+class ExistingSystemError(PluralKitError):
+    pass
+
+
+class DescriptionTooLongError(PluralKitError):
+    pass
+
+
+class TagTooLongError(PluralKitError):
+    pass
+
+
+class TagTooLongWithMembersError(PluralKitError):
+    def __init__(self, member_names):
+        self.member_names = member_names
+
+
+class CustomEmojiError(PluralKitError):
+    pass
+
+
+class InvalidAvatarURLError(PluralKitError):
+    pass
+
+
+class AccountAlreadyLinkedError(PluralKitError):
+    def __init__(self, existing_system):
+        self.existing_system = existing_system
+
+
+class UnlinkingLastAccountError(PluralKitError):
+    pass