Smoother transition animations on the new UI example theme.

[nitzanballerine]

Description

In order to make the experience of using the new UI them more appealing and trustworthy, the transitions between steps in the flow should be smoother.

###Tasks

• When clicking a button, make it so that the during the transition animation the background remains black instead of disappearing.

###Examples and references
Enter: https://examples-future.ballerine.app/ and see the colors and texts throughout the flow.

[tejash023]

Hey, Can I work on this?

[alonp99]

@tejash023 Sorry, missed your comment - sure, we are available in slack for questions

[alonp99]

Closing as web-sdk in under massive refactor, this will probably not be relevant