MDL-46155 core_component: functions to retrieve list of existing classes
MDL-46155 report_eventlist: use new core function to find classes list
MDL-45916 tool_monitor: Add basic file structure of the report
MDL-45916 tool_monitor: Adding xml file defining the db tables
MDL-46109 tool_monitor: Implement a class to get list of events and other related apis
MDL-45939 tool_monitor: Implement a class that represents a rule instance
MDL-46131 navigation: updates to navigation

This patch does the following:-
Start using proper key for course report node
Allow admin tools to hook into course navigation
MDL-46131 tool_monitor: Build the navigation tree for the tool
MDL-45919 tool_monitor: Add a subscription manager class
MDL-45918 tool_monitor: Rule manager class, unit tests and data generators.
MDL-45918 tool_monitor: Polish the code for rule manager and unit tests
MDL-45938 tool_monitor: Initial version of rule form.
MDL-45938 tool_monitor: Add a yui module to handle event selection dropdown
MDL-45938 tool_monitor: Add support for editing/creating a rule
MDL-46110 tool_monitor: Create renderable and renderer for manage rules page
MDL-46110 tool_monitor: Display a rule managment interface
MDL-46130 tool_monitor: Handle rule managment
MDL-46241 tool_monitor: Create a class that represents a subscription instance
MDL-46111 tool_monitor: Add a renderer for the subscription page
MDL-46111 tool_monitor: Add renderables for the subscription page