Refactor opener intercepts #24
Description
Right now we have a lot of instanceof checks and we're really using the DefaultLegacyOpener in two different ways.
If we come from an open path where we are given a String source, then if the LegacyOpener fails we want to continue to IJ1 with our given source.
If we come from an open path where we weren't given a String source and one is chosen during IJ2 execution, which then fails, we want to continue to IJ1 with the source selected in IJ2.
In the second case we ALWAYS want to return the path from IJ2. In the first case, we don't care about the String and it's effectively the same as a null value.