Refactor dashboard code

[frenchbread]

As an Apinf developer I want to easily reuse functions that are used there.

• Refactor code to be more easy to read and maintain.
• If the logic architecture allows it, try to make code more object oriented

Since this is not creating any new functionality, but rather improving existing one, do not spend more than 1 hour on this task.

Definition of done

• Dashboard contains no functions with subfunctions
• If possible, dashboard functions are objects with methods
• Most or all of ElasticSearch variables are parametrized
• Code is easy to read
• Code contains comments

[brylie]

@frenchbread is this a work in progress or should we wait for the Dashboard sprint?

[frenchbread]

@brylie It's not in progress, so let's take this issue to the dashboard sprint.

[frenchbread]

Testing out refactored version of updated dashboard in this repo.

Still having two issues:

• Data fetch takes too much time (even though it has been optimized)
• "Average response time" chart does not work

[brylie]

@frenchbread tried an approach where we stored analytics in the MongoDB instance, but the performance was slow when serving > 10,000 records:

We decided to revert to using the Meteor server to relay the Elastic analytics data. This isn't 'perfect', but it seems to improve the situation we are trying to solve (issue #1105).