Improve accessibility by adding more aria support

[PontusKberg]

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?

[ ] 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: #4707

What is the new behavior?

Added additional aria roles, labels and states to a select number of components

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

These changes are intended to increase the accessibility of some NG-ZORRO components. There are still many more components whose accessibility can be improved, but which are not addressed by this PR.

[codecov]

Codecov Report

Merging #5658 into master will decrease coverage by 0.00%.
The diff coverage is 84.09%.

@@            Coverage Diff             @@
##           master    #5658      +/-   ##
==========================================
- Coverage   90.31%   90.30%   -0.01%     
==========================================
  Files         455      455              
  Lines       13788    13828      +40     
  Branches     2258     2189      -69     
==========================================
+ Hits        12452    12488      +36     
+ Misses        819      814       -5     
- Partials      517      526       +9     

Impacted Files	Coverage Δ
components/menu/menu-item.directive.ts	75.80% <ø> (ø)
components/menu/submenu-inline-child.component.ts	91.66% <57.14%> (-8.34%)	⬇️
...ponents/menu/submenu-non-inline-child.component.ts	79.41% <62.50%> (-5.78%)	⬇️
components/dropdown/dropdown.directive.ts	88.88% <80.00%> (-0.48%)	⬇️
components/dropdown/dropdown-menu.component.ts	90.47% <100.00%> (+0.47%)	⬆️
components/icon/icon.directive.ts	95.45% <100.00%> (+0.29%)	⬆️
components/input-number/input-number.component.ts	97.48% <100.00%> (+0.02%)	⬆️
components/menu/menu.directive.ts	90.16% <100.00%> (+0.33%)	⬆️
components/menu/menu.service.ts	91.30% <100.00%> (+3.06%)	⬆️
components/menu/submenu.component.ts	98.92% <100.00%> (+0.04%)	⬆️
... and 6 more

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[mixalistzikas]

Any progress on this ticket?

[wzhudev]

@PontusKberg Hi! Thanks for openning this PR. It seems that there are some merging conflicts. Could you please resolve them?