ui: dropdown - dropdown is not opened when click on mat-form-field container

[SuperITMan]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/NationalBankBelgium/stark/blob/master/CONTRIBUTING.md#got-a-question-or-problem

Current behavior

When click on mat-form-field container instead of the dropdown input, the dropdown is not opened.

Expected behavior

When click on mat-form-field container instead of the dropdown input, the dropdown should be opened as it is the case with MatSelect element from Angular Material.

Minimal reproduction of the problem with instructions

Put your mouse as show in the following image and click. Nothing happens...

What is the motivation / use case for changing the behavior?

fixing bug

Environment

Angular version: X.Y.Z
Stark version: 10.0.0-beta.8


Browser:
- [ ] Chrome (desktop) version XX
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX
 
For Tooling issues:
- Node version: XX  
- Platform:  

Others: