Add hooks to enable customization by users

[villfa]

There are 2 events I have in mind:

• AfterFileAnalysis
• AfterAnalysis

The users could hook on the event of their choice by implementing the corresponding interfaces.

Example:

interface AfterFileAnalysisHook {
    public function afterFileAnalysis(AfterFileAnalysisEvent $event): void;
}

interface AfterFileAnalysisEvent {
    public function getFilePath(): string;
    public function getNumberOfChanges(): int;
    public function getCyclomaticComplexity(): int;
    //public function getScore(): float; // nope, the scores are calculated at the end
}

interface AfterAnalysisHook {
    public function afterAnalysis(AfterAnalysisEvent $event): void;
}

interface AfterAnalysisEvent {
    public function getNumberOfFiles(): int;
    public function getMaxNumberOfChanges(): int;
    public function getMaxCyclomaticComplexity(): int;
    public function getMaxScore(): float;
}

[villfa]

I'm wondering it the hooks methods shouldn't be static. That way we don't have to worry about how to instantiate the hooks.