MDL-47152 tool_monitor: fixed typo
MDL-47152 core: edited get_formatted_help_string to accept string parameters
MDL-47152 tool_monitor: added help icon renderer
MDL-47152 tool_monitor: added help icon for subscriptions
MDL-47152 tool_monitor: added help icon for rules
MDL-47460 tool_monitor: add missing alt on manage icons
MDL-46132 tool_monitor: Add a new message provider
MDL-46132 tool_monitor: Add a adhock task to send notifications
MDL-46132 tool_monitor: Add a universal event observer

This observer does the following task:-
1) It monitors all events and stores relevant data in a temporary table
2) It doesn't write the events straight away, it buffers them, so there is only one db write per request
3) It calculates and sees if there are subscriptions related to those events who need to be notified
4) If there are such cases, it generates the message to send and schedules a adhoc task for the same
MDL-46132 tool_monitor: Add unit tests for the universal observer
MDL-46132 review changes