Externalize hook execution

## Problem

Since taskchampion exists, writing something that interfaces with the Taskwarrior's tasks is quite easy and incentivizes people to stop shelling out to the `task` command. Whilst using the taskchampion library improves the task handling immensely, it also comes at the hefty cost of completely ignoring the original Taskwarrior hooks.
For example, if a command starts a task via taskchampion tracking the spend time of the task via the Timewarrior record hook would silently stop working.

## Proposed improvement

It is obviously impartial to try to bolt hook execution on the taskchampion library;
Rather, externalizing the hook execution to another library would be beneficial as that would than guarantee that both Taskwarrior and the external command execute hooks in same way.

Otherwise, the external command could try to reimplement the hook execution, but this would probably end in slight changes in behaviour and certainly in code duplication.