Update the TrustChain implementation to match the algorithm described in the publication

[devos50]

The TrustChain algorithm described in the latest publication has a few key differences compared to the original implementation:

• Each record has multiple back-pointers which decreases the fraud detection time (see the experiment in Figure 10).
• Support for sharing inconsistencies/fraud (pairs of records) with other users.

The code used in the paper can be found here but is tightly integrated with the simulation code. We should extract the core parts and include them in BAMI.