Improve overriding dimens in SDC

[FikriMilano]

Is your feature request related to a problem? Please describe.
In client app, I want to override the dimens property to change the margin or padding of the UI components. But if I change a dimens property that is used in the component I like to change, it also affects the other components. Because those dimens property is used in both components.

e.g. padding_default is used as margin top of widgets and padding of check box, overriding this property will affect both, which I don't want to happen.

Describe the solution you'd like
Overriding a dimens property should only affect the component people intend to change.

Describe alternatives you've considered
N/A

Additional context
This is related to the UX Questionnaire adjustments that is ongoing on FHIRCore opensrp/fhircore#1974.

Current design =================> Adjusted design

In summary of our UX changes that depends on SDK:

• Reduce margin between question and body, should be 16px
• Add more margin between widgets, should be 32px
• Reduce margin between selection options, should be 8px

Would you like to work on the issue?
Yeah

[FikriMilano]

@shelaghm @f-odhiambo

[FikriMilano]

@jingtang10 are you going to work on this? or should I?

[jingtang10]

@santosh-pingle please take a look at this PR!

[jingtang10]

@shelaghm fyi