[BACKEND] Create a MockPyd2bot for tests

[hadamrd]

This MockPyd2bot will be a sub class of Thread that will have same init params as Pyd2bot
In its main loop:

• Loggs randomly in its logger
• Send random update events to the updates listener

This class will allows us to run bot runs and stop logic without having to connect with a real bot account

Improve this class over time to implement more robust tests