Micro-optimization: Use memory friendly data structures.

[kevingamez]

There are more than 30 files where Dart Maps are used. The recommendation to transition from LinkedHashMap to HashMap in the Kalium codebase is regarded as a micro-optimization due to its narrow focus on a specific implementation detail. In this case, the proposed change concentrates solely on the memory footprint of the Map data structure. While memory efficiency is undoubtedly a crucial consideration, especially in mobile development where resources are constrained, the impact of this modification might be limited. Moreover, the overall impact on the application's performance should be assessed through profiling and benchmarking, as optimizing a specific code snippet in isolation may not necessarily translate into significant improvements at the application level.