Multi src astar (#594)

## Description:
Samples border shore tiles and uses multi-a* for determining the
transport ship spawn cell.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

<DISCORD USERNAME>
evan

---------

Co-authored-by: evan <openfrontio@gmail.com>

src/core/execution/PortExecution.ts

@@ -76,7 +76,7 @@ export class PortExecution implements Execution {
     }
 
     const port = this.random.randElement(ports);
-    const pf = PathFinder.Mini(this.mg, 2500, false);
+    const pf = PathFinder.Mini(this.mg, 2500);
     this.mg.addExecution(
       new TradeShipExecution(this.player().id(), this.port, port, pf),
     );