Modify plugin class

Add Plugin counter class PluginCounter.
And, modify Plugin class to using PluginCounter on create a instance.
You can get the number of a plugin instance `$plugin->getId();`

## MUST

### :exclamation:  Overriding constructor
If you override `__construct`, call `parent::__construct` at the top.

I found and fixed below plugin overided constructor.
* ColsPlugin

### :exclamation: Using getId
If you already declare the function `getId()` or call counting feature, delete them and use this counting feature.


## PluginCounter

This class has count list of Plugins.

```javascript
{
  IconPlugin: 1,
  ColsPlugin: 10,
 :
}
```

### Usage

* increment:  `PluginCounter::inc('IconPlugin')` 
* get count: `PluginCounter::get('IconPlugin');`
* get all count: `PluginCounter::all();`