feat: add plugin support to ngu-flow

[sheikalthaf]

Introducing Plugin support, main focus is to tree shake the features and easy to use

export interface FlowPlugin {
  onInit?(data: FlowComponent): void;
  afterInit?(data: FlowComponent): void;
}

In this PR currently two plugins added.

1. Fit to window
2. scroll into view

Usage example

<ngu-flow [config]="config">
...
</ngu-flow>

export class DemoComponent {
   plugins = {
      scroll: new ScrollIntoView('1'),
      fitToWindow: new FitToWindow(true),
      arrange: new Arrangements(),
   };
   config: FlowConfig = {
      Arrows: true,
      ArrowSize: 20,
      Plugins: this.plugins,
  };

  focusNode(id: string) {
    this.plugins.scroll.focus(id);
  }

  fitToWindow() {
    this.plugins.fitToWindow.fitToWindow();
  }
  
  autoArrange() {
    this.plugins.arrange.arrange();
  }
}

This is the basic example of the plugin usage.

[santoshyadavdev]

Can we add some description what we mean by plugin and which plugin we are going to support?

[sheikalthaf]

@santoshyadavdev Yes, for now I'm just exploring how we can add plugin support so that i can be more versatile. Can you throw some idea about general plugin, how they designed?

[sheikalthaf]

@santoshyadavdev can you check this proposal for plugin

[santoshyadavdev]

_functions generally are used for private functions, can you remove _ if possible.

[sheikalthaf]

Yes, it is a private functions only, only for testing purpose i just made in public. Do you have any alternative to access this functions in testcases

[santoshyadavdev]

same her lets remove _ from functions

[sheikalthaf]

Just for testing purpose made it public and added _

[santoshyadavdev]

yes it should be testes with public methods, call the public methods and check

[santoshyadavdev]

Just added sonar cloud to this project as well

[sheikalthaf]

@santoshyadavdev addressed most of the comments and also solved the issues reported by sonar

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues

Measures
0 Security Hotspots
No data about Coverage
1.6% Duplication on New Code

See analysis details on SonarCloud

[sheikalthaf]

@santoshyadavdev this PR is ready for review, can you do the final review once

[santoshyadavdev]

we should remove the private apis, but let me know if we want to merge this and want to take care of this later.

[sheikalthaf]

@santoshyadavdev for now we are good with the plugin implementation, later I'll change the testcases and avoid public methods.

[santoshyadavdev]

Cool let's merge it

[sheikalthaf]

@santoshyadavdev Need your approval to merge