Added Stats chart for org template usage

Updated Usage page display to fix several issues. ...

- Moved mouse pointer instruction.
    - Made textual changes to "No. of plans by template"
    - The bar charts for  "No. users joined during last year" and
    "No. plans during last year" months are in ascending order. They were
    in descending order previously. Updated the count statistics methods
    in statistics_controller.rb.
    - The "No. plans by template" bar chart is now  replaced by a stacked bar chart
    as this is visually better for large data.
    - updated the by_template method in the create_or_update.rb with code from @xsrust.
    This now aggregates template counts for a month correctly.

    Fix for issue #1679.

updated Role, Plan logic and fixed tests

1. stat_created_plan.to_csv with option for details by template. ...

2. details attribute for stats table #1679
3. create_created_plan_service extended with details by template
4. create_last_month_created_plan_service extended with details by
template.
5. create_or_update strategy for generating stats
6. StatCreatedPlanByTemplateController#index for graphs usage
7. month_start_date and month_end_date for OrgDateRangeable class

[RD-1679] Usage view including date input for plans by template

[#1679] monthly_range query updated

[#1679] client-side chart for plans by template

[#1679] Time picker for plans by template chart

[#1679] Download plans by template action.

deleted spec

merge conflicts fixed

[#1679] Removed JS linter warnings

[#1679] Rubocop conforming code. Drying out stat services