Redux performance

[alexsegura]

Since dispatch screen was introduced, there seems to be a problem with performance. Users are reporting that the app is slow, and takes long to perform some actions, like task completion.

This may be linked to the fact that we are now loading all the tasks of the day on dispatch screens, and this may consume a lot of RAM. Also, operations on the state may consume a lot of memory, as we are making copies of arrays all the time.

There can be several ways to improve RAM usage.

• [ ] Add a way to measure performance in production (response times, memory consumption)
• [ ] Reduce the body size of task API responses by removing unused keys.
• [ ] Optimize state size/memory consumption

See FAQ about Redux performance for general considerations about optimizing the state.

[Paul-Eraman-CoopCycle]

Status? @alexsegura