Tweak "Return to Molecule Builder" button

[SebastianIsSeabass]

The button "Return to Molecule Builder" Is render a little too tall, and where possible shouldn't drop below the fold as it is necessary navigation for user to return to the builder

Reference: https://miro.com/app/board/uXjVKAZKZ84=/?moveToWidget=3458764593762512505&cot=14

Acceptance criteria:

the button should match the rest of the UI's button heights or be matched to other elements in the UI, where possible the keep the button above the fold so the user can navigate away from this page