[MNT-22051] - Fix form field mapping when value is zero

[SilviuCPopa]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x")

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation
• Other... Please describe:

What is the current behaviour? (You can also link to an open issue here)

https://alfresco.atlassian.net/browse/MNT-22063

What is the new behaviour?

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[eromano]

unit test missing

[codecov-io]

Codecov Report

Merging #6517 (f602cdd) into develop (8dd43ef) will increase coverage by 0.19%.
The diff coverage is 75.00%.

@@             Coverage Diff             @@
##           develop    #6517      +/-   ##
===========================================
+ Coverage    76.22%   76.42%   +0.19%     
===========================================
  Files          869      859      -10     
  Lines        19619    19352     -267     
  Branches      3906     3837      -69     
===========================================
- Hits         14955    14790     -165     
+ Misses        3469     3386      -83     
+ Partials      1195     1176      -19     

Impacted Files	Coverage Δ
...d/src/lib/form/models/task-variable-cloud.model.ts	20.00% <50.00%> (+20.00%)	⬆️
...ib/core/form/components/widgets/core/form.model.ts	92.81% <100.00%> (+4.65%)	⬆️
lib/core/directives/directive.module.ts	100.00% <0.00%> (ø)
...load/components/upload-version-button.component.ts	40.00% <0.00%> (ø)
lib/extensions/src/lib/services/rule.service.ts
.../components/dynamic-component/dynamic.component.ts
...sions/src/lib/services/extension-loader.service.ts
lib/extensions/src/lib/config/extension-utils.ts
...b/extensions/src/lib/services/extension.service.ts
lib/extensions/src/test.ts
... and 6 more

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