Create analyserscan which does an additional loop of iterations

[oliwenmandiamond]

For B07, there specs analyser detectors in GDA do each iteration separately from each other. We should be able to replicate this behaviour but in a plan instead. What we need to do is intercept the region for a ElectronAnalyserRegionDetector and replace the iteration to always be 1. We then create an additional loop inside per_step and loop through the correct number of iterations.