MDL-45758 tool_monitor: Adding xml file defining the db tables

Original issue - MDL-45916
MDL-45758 tool_monitor: Implement a class to get list of events and other related apis

Original issue - MDL-46109
MDL-45758 tool_monitor: Implement a class that represents a rule instance

Original issue - MDL-45939
MDL-45758 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

Original issue - MDL-46131
MDL-45758 tool_monitor: Build the navigation tree for the tool

Original issue - MDL-46131
MDL-45758 tool_monitor: Add a subscription manager class

Original issue - MDL-45919
MDL-45758 tool_monitor: Rule manager class, unit tests and data generators.

Original issue - MDL-45918
MDL-45758 tool_monitor: Polish the code for rule manager and unit tests

Original issue - MDL-45918
MDL-45758 tool_monitor: Initial version of rule form.

Original issue - MDL-45938
MDL-45758 tool_monitor: Add a yui module to handle event selection dropdown

Original issue - MDL-45938
MDL-45758 tool_monitor: Add support for editing/creating a rule

Original issue - MDL-45938
MDL-45758 tool_monitor: Create renderable and renderer for manage rules page

Original issue - MDL-46110
MDL-45758 tool_monitor: Display a rule managment interface

Original issue - MDL-46110
MDL-45758 tool_monitor: Handle rule managment

Original issue - MDL-46130
MDL-45758 tool_monitor: Create a class that represents a subscription instance

Original issue - MDL-46241
MDL-45758 tool_monitor: Add a renderer for the subscription page

Original issue - MDL-46111
MDL-45758 tool_monitor: Add renderables for the subscription page

Original issue - MDL-46111
MDL-45758 tool_monitor: Update subscription manager class to support the subs renderable

Original issue - MDL-461111
MDL-45758 tool_monitor: Add a UI page to manage subscriptions

Original issue - MDL-46111
MDL-45758 tool_monitor: Add an observer to delete data when course is deleted

Original issue - MDL-46510