feature: implement stepper component

[LighthouseKeeperYN]

close #2245

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement/refactoring (non-breaking change that doesn't add any feature but make things better)

[rustem-nasyrov]

Good job. Have you used any references while you implemented this component?

• Vuetify' stepper
• Quasar' stepper

I have a concerns about using templates instead of creating va-step-item component (or something similar).

• We missing finish button on the last step.

• Vertical example looks odd.

For example how it implemented in references

[rustem-nasyrov]

Also will be better to redo this demo. Imo it's also looks odd compared to the whole vuestic design.

[m0ksem]

Two way:

<VaStepper>
   <MyStepOne #step-0 />
   <MyStepTwo #step-1 />
   <MyStepThree #step-2 />
</VaStepper>

<VaStepper>
  <VaStepItem>
    <MyStepOne />
  </VaStepItem>
  <VaStepItem>
    <MyStepTwo />
  </VaStepItem>
   <VaStepItem>
     <MyStepThree />
  </VaStepItem>
</VaStepper>

[LighthouseKeeperYN]

Good job. Have you used any references while you implemented this component?

• Vuetify' stepper
• Quasar' stepper

I have a concerns about using templates instead of creating va-step-item component (or something similar).

• We missing finish button on the last step.

• Vertical example looks odd.

For example how it implemented in references

Too difficult at this point.
#2971

[rustem-nasyrov]

Vue-book' demo doesn't work, but I suggest to move it to the new issue with known issues and suggestions for this component.

[aluarius]

The component should be accessible: keyboard navigation + aria attributes.

https://docs.telerik.com/kendo-ui/controls/navigation/stepper/accessibility/keyboard-navigation
https://stackoverflow.com/questions/52932018/making-a-step-progress-indicator-accessible-for-screen-readers