feat(module: slider): slider add ngModel

[sWhite01111]

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• Tests for the changes have been added (for bug fixes / features)
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PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Other information

[codecov]

Codecov Report

Merging #202 into master will increase coverage by 0.06%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #202      +/-   ##
==========================================
+ Coverage    86.4%   86.46%   +0.06%     
==========================================
  Files         224      224              
  Lines        7185     7204      +19     
  Branches     1006     1008       +2     
==========================================
+ Hits         6208     6229      +21     
  Misses        573      573              
+ Partials      404      402       -2

Impacted Files	Coverage Δ
...ents/slider/slider-steps/slider-steps.component.ts	92.18% <ø> (ø)	⬆️
...ts/slider/slider-handle/slider-handle.component.ts	89.2% <ø> (+0.63%)	⬆️
...ents/slider/slider-track/slider-track.component.ts	100% <ø> (ø)	⬆️
...ents/slider/slider-marks/slider-marks.component.ts	92.85% <ø> (+1.42%)	⬆️
components/slider/slider.module.ts	100% <ø> (ø)	⬆️
components/slider/slider.component.ts	100% <100%> (ø)	⬆️

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[fisherspy]

   private onChangeFn: (value: number) => void = () => {};

   private onTouchFn: (value: number) => void = () => {};

pls change this two statements into:

  private _ngModelOnChange: (value: number) => void = () => {};

  private _ngModelOnTouched: () => void = () => {};