feat(business): implement tabs

[tyzess]

Closes #87

[kyubisation]

Thank you very much for your contribution 😃
Looks very good already. I've requested some changes.

[kyubisation]

@Frenggi Can you have a look at https://angular-staging.app.sbb.ch/210/business/components/tabs

[Frenggi]

Hi @kyubisation
The initial implementation looks ok. But the intent was to show tabs like they are known from RCP applications. Therefore the inactive tab is not as designed. Inactive != disabled. --> check attached image.

I'm aware, that this design is a bit trickier to implement in a component than the one for tabs in public library. Therefore we might have to discuss what possibilities we have as a compromise between design and the implemented component.
The second point is the pill: there it would be great to place it inside the frame of the tab. But, I understand that you tried to reuse the component implementation from the public library. And therefore I'm not sure if it would be possible to place it inside.

[tyzess]

@Frenggi Thanks for the hint. I confused inactive with disabled. Could you update https://designsystems.app.sbb.ch/en/webapps/components/tab and add a spec for disabled tabs?
Regarding the pills, they just came with the port from public to business. Until now I just ignored them.

[tyzess]

@kyubisation Is the build pipeline currently broken?

[kyubisation]

I switched from travis-ci to github actions, however there was a problem with the scripts name, which I fixed just now. You can rebase on master and then it should work.
Sorry for the slow response on this PR. I will have a meeting on monday with @Frenggi in regard to the disabled tabs. Afterwards I'll come back to this.

[tyzess]

@kyubisation Any update? We'd appreciate it if we could use the tabs in our projects soon...

[kyubisation]

@uzysset Please rebase the PR on top of master and force push the changes. We will merge it as it currently is and open another issue for adaptation to the new design spec.

[kyubisation]

LGTM 😃
Thank you very much!