[Task] Extend Dashboard layout to grid with user-defined card sizes

[andrewazores]

After #728, the Dashboard layout system should be further extended to a Grid:

https://www.patternfly.org/v4/layouts/grid

When a user adds a card to the grid it should have a default size, specified by the type of card being added. This default should be the minimum size that the card can reasonably render and display its content. The top right action menu should have a Resize action that allows the user to change the size of the card and expand it, or bring it back down to the default/minimum. The default value should be indicated in the resize dialog content. This size should also be persisted in the dashboard layout. The card layout will still be modelled as a stack or list, but the rendering on screen will allow smaller cards to be rendered side-by-side, forming rows, instead of forcing a vertical stack orientation.