Simpit V2.1.2

Features

Allow DTR flag to the serial connection (seems to have no impact with Arduino connection and allow connection from a Pi Pico).

Bugfixes

Fix a NullReference that prevented the use of the custom ressource message
Fix a NullReference happening on Mac on the target provider, when switching vessel
Fix an issue where after a reconnection, no channel subscription was possible to a previously subscribed channel
Set the AssemblyVersion correctly in the generated DLL