feat: add Stats API

[ravinderk]

User Story

As an admin, I want reports to generate faster for large DB so that performance is improved.

As a developer I want an easy way to query report data using an API that's easy to interact with.

Predefined report periods:

Current Behavior

Earning calculation logic runs when page load or admin request for it. On the page load, a calculation can cause of 500 error.

Expected Behavior

Way to calculation earning on time on donation completes (async process if needed).

Related

https://docs.google.com/document/d/1bOo3NDyCwTGXxxqXq568bOC8TeNQKOUzYk-fah6-tSw/edit#

Acceptance Criteria

The main focus of Stats API is to get date based sale and earning data. There is the following area where we will start using this:

• Dashboard Give widget
• Donor Listing Page
• Donor detail page
• Donor wall shortcode ( done in fix: correct default behavior of donor wall #3744 )
• Addons (need to check)

[kevinwhoffman]

@ravinderk Can you provide an update on this issue before this week's call? I would like to see this converted to an epic and broken out into smaller issues with acceptance criteria so that we can get a better sense of the progress being made. I see the commits, but it's hard to understand what they are working towards. Thanks.

[ravinderk]

@kevinwhoffman I agreed with you. I will make this issue Epic with subtasks.

[ravinderk]

@kevinwhoffman @DevinWalker We updating donor wall logic that gives us the idea to improve meta query to get stats. I am closing this issue in favor of creating a new one with update scope and acceptance criteria.