Show Data Skeleton Loading

[Bonapara]

Desired Behavior

(See #4462 for videos)

Thanks to prefetch loading, we can now display the correct number of field lines and their names. It's time to launch the content loading:

https://www.figma.com/file/xt8O9mFeLl46C5InWwoMrN/Twenty?type=design&node-id=25429-70096&mode=design&t=75yrmyKfqMepmFVt-11

[FelixMalfait]

Assigned to @saadfrhan

[gitstart-twenty]

Hey @Bonapara, Mind sharing a resource so we can get more familiar with prefetch loading?

[gitstart-twenty]

Hey @Bonapara Should the skeleton in the timeline be the width of the tabs at the top, or 440px like in the design?

[Bonapara]

440px is ideal, I fear a larger size would be overwhelming. Thanks!