refactor: builtin actions

[mkanoor]

Each action is a separate class
Allows for us to share code between different actions in a Helper class
Each action can be tested independently by injecting the required events

[Alex-Izquierdo]

Is there a reason to use the __call__ internal method?

I'm concerned about the approach to using the internal method __call__ to run the logic of the action. I feel is not a good usage of this method and that method will be executed every time the object is called. It obfuscates the interface of the action, specially if we want to support pluggable actions. I feel the action should be executed through an ad-hoc "run" method. This seems to be the same pattern followed by plugins and modules in ansible.

[benthomasson]

This conflicts with having actions be simple functions. Functions are easier to test since they have no internal state. It also makes a plugin architecture harder since plugins have to inherit from a base class. I am generally against inheritance for code reuse. I prefer composition to inheritance using the delegation pattern: https://en.wikipedia.org/wiki/Delegation_pattern.

[mkanoor]

@benthomasson Please re-review I have used a Helper class to keep the shared code between the different actions.

[Alex-Izquierdo]

Isn't this PR leaving dead code in the repo?

[mkanoor]

Isn't this PR leaving dead code in the repo?

@Alex-Izquierdo Yes it will be removed in a different PR, since this PR was open for a while deleting the file and rebasing every time was a challenge.

#598