Refactors spec/product/reports_spec.rb
Refactors spec/product/reports_spec.rb

This makes the doc output for this report MUCH easier to determine
failures in specific reports and reads better in doc format:

**BEFORE**

    YAML reports
      is not empty
      defines correct (existing) col_order columns
      defines fields for reporting by fully qualified name
      can be build even though without data
      defines headers that match col_order

**AFTER**

    YAML reports
      regular reports
        100_Configuration Management - Virtual Machines/031_Unregistered VMs
          defines correct (existing) col_order columns
          defines fields for reporting by fully qualified name
          can be built even though without data
          defines headers that match col_order
        190_Configuration Management - Physical Servers/020_Server Health
          defines headers that match col_order
          defines correct (existing) col_order columns
          defines fields for reporting by fully qualified name
          can be built even though without data
        760_Trending - Storage/110_Datastore_Capacity_Trend_over_6 mos
          defines fields for reporting by fully qualified name
          defines correct (existing) col_order columns
          defines headers that match col_order
          can be built even though without data
        ...
      chart reports
        miq_reports/vmdb_table
          defines headers that match col_order
        miq_reports/vim_perf_planning
          defines headers that match col_order
        miq_reports/vim_perf_tophour
          defines headers that match col_order
        ...
      product directory
        is not empty and contains reports

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic