Bug 26486: Group edit buttons in reports toolbar

Bug 26486: Group edit buttons in reports toolbar

This patch modifies the reports interface to change the reports toolbar
in two ways:

1. The Edit, Duplicate, and Delete buttons are now combined into a
   button menu. My original idea was to have it be a split button, but
   the logic for handling various permissions made the template logic
   too convoluted.
2. The "Show SQL code" button is converted to a "Single toggle" button
   (https://getbootstrap.com/docs/3.3/javascript/#buttons-single-toggle).
   This type of button is specifically designed for this kind of
   interface element.

This patch includes indendation changes, so please diff accordingly.

To test, apply the patch and go to Reports -> Saved reports.

- Logged in as a user with Create and Delete report
  permissions:
  - View an SQL report. In the toolbar you should see an "Edit" button
    menu with three options: Edit, Duplicate, and Delete. Check that all
    work correctly, including a deletion JavaScript confirmation dialog.

- Logged in as a user with Create but not Delete report permissions, you
  should see an "Edit" button menu with two choices: Edit and Duplicate.

- Logged in as a user with Delete but not Create report permission (??)
  you should see only a standalone delete button.

- Logged in as a user with Execute report permission, run an SQL report.
  Test the "Show SQL code" button. The text should change to "Hide SQL
  code" and the button should be styled to look like its "pressed"
  state.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>