[toolchains] Editor should not allow for duplicated connections
Our toolchain editor currently allows the user to draw duplicated connections from a block to another block, while this should be illegal.
Steps to reproduce:
- For any toolchain
- On the editor, create a new connection duplicating an existing one
- Type a name and hit the save button
Error for duplicated connection, with cryptic message.
Either a more explicit error message indicating which connections are duplicated or a smarter toolchain editor that does not allow for this.