Refactor Senders initialization

[Dimedrolity]

Overview

We have Sender interface with Init method that configures Sender.

// Sender interface for implementing specified contact type sender
type Sender interface {
	SendEvents(events NotificationEvents, contact ContactData, trigger TriggerData, plot [][]byte, throttled bool) error
	Init(senderSettings map[string]string, logger Logger, location *time.Location, dateTimeFormat string) error
}

Problem

It is strange approach to configure entity, each Sender can have its own settings and dependencies.

Now we have logger, location *time.Location, dateTimeFormat string, I think authors (developers) wanted to don't repeat yourself and created that unified Init method. Maybe will be better extract BaseConfig struct and maybe Config struct for each Sender.

If we follow DI principle, then constructor func (that have dependencies) and Init method in one time is not well, both methods goal is to configure.

Solution

Need to create constructor functions for each Sender, and move init logic from Init method to constructors, then remove Init from interface and impelementrations.