Fix minor implementation issues

[maxkratz]

There are some minor implementation issues left, typically marked with a TODO.

• Pipeline-based algorithms: "Normal" memory metrics are broken.
• CsvUtil error handling. https://github.com/maxkratz/iflye/blob/1bc84da8d29f8ef0b6f89b848bca2d90db743fe0/vne.scenarios/src/scenario/util/CsvUtil.java#L220
• GlobalMetricsManager temporary evaluation fix. https://github.com/maxkratz/iflye/blob/1bc84da8d29f8ef0b6f89b848bca2d90db743fe0/network.metrics/src/metrics/manager/GlobalMetricsManager.java#L190
• Use better data structures in some classes, e.g., use UnifiedMap from the Ecplise Collections in the class IncrementalGurobiSolver for a possible minor performance boost.