fix(module:input-number): fix display value after formatter changed

[suraciii]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] 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?

After nzFormatter changed, the text on element will not apply the new formatter, unless changes value or unfocus.

What is the new behavior?

Text updates immediately if formatter changed.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[vthinkxie]

please update your code to fix ci.

[codecov]

Codecov Report

Merging #1371 into master will increase coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1371      +/-   ##
==========================================
+ Coverage   97.02%   97.07%   +0.04%     
==========================================
  Files         196      196              
  Lines        8339     8402      +63     
  Branches     1102     1136      +34     
==========================================
+ Hits         8091     8156      +65     
  Misses         31       31              
+ Partials      217      215       -2

Impacted Files	Coverage Δ
...mponents/input-number/nz-input-number.component.ts	100% <100%> (+1.05%)	⬆️

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[vthinkxie]

@csyszf please add test for the change, thanks.

[suraciii]

@vthinkxie test added.

[vthinkxie]

should be this.getCurrentValidValue(this.actualValue)

[suraciii]

@vthinkxie
If formatter is configured like value => `${value} %` and default value not been set, the display text will be "undefined %"
should it be considered a bug?

[vthinkxie]

@csyszf maybe not I think.