Exclude Trending reports from Dashboard widgets.

Changed code to exclude Trending reports from widget editor because those are not like regular reports and do not have columns. Show a message instead of third pull-down "No Reports to select" in the view.

https://bugzilla.redhat.com/show_bug.cgi?id=1163952
Refactored code in schedule_menus method.

- Renamed schedule_menus method to report_selection_menus, and changed all it's callers.
- Moved report_selection_menus method to reports controller, as it is a common method schedules and widgets editor.
- Added spec tests for report_selection_menus method
- Changed message to be displayed for folders that do not have reports .

https://bugzilla.redhat.com/show_bug.cgi?id=1163952
Converted view to haml.

- Used gettext to display "No Widget compatible Reports found" message.

https://bugzilla.redhat.com/show_bug.cgi?id=1163952
Fixed misspelled "capitalize" and added flash message to view

Fixed misspelled "capitalize" when creating error message for adding duplicate Compute Chargeback Rate
Added flash message definition to Chargeback Edit view

https://bugzilla.redhat.com/show_bug.cgi?id=1073366
Merge pull request #1159 from GregP/chargeback_rate_capitalize_msg

Fixed misspelled method name (capitalize)
Merge pull request #1115 from h-kataria/exclude_trending_reports_in_dashboard_widget_editor

Exclude trending reports in dashboard widget editor