Adding type ResizableContentWidget - using it for the content hover widget

[aiday-mar]

Fixes #14165

This PR defines the types ResizableContentWidget which can be used to implement resizable content widgets. The PR also introduces the SingleSizePersistingMechanism and the MultipleSizePersistingMechanism which can be used to define method for persisting the widget sizes. The first class saves a single persisted size while the second class saves persisted sizes on a per-token basis.

In addition to these abstractions, the PR also adds the possibility to resize the content hover. It uses the above abstractions. Some notes about the PR:

• The height is limited by the current total height of the hover widget given the current width. It is possible that the no cap is put on the maximum rendering height. (TBD)
• The width is limited by the width of the screen.
• The content hover is positioned with regards to the positioning preference (above or below) in the settings. If there is no space, it is placed on the other side. If the widget size has been persisted to a size that does not fit in the current screen, a smaller size than the persisted size is used.
• For the time being, as soon as the widget hover is resized, the size is persisted for the duration the VS Code window is active or until refreshing the page. The hover sizes are persisted on a per token basis. It is possible that this functionality is removed and the hover sizes are not persisted at all (TBD)

Below you may find an example of the content hover resizing.

Screen.Recording.2023-03-23.at.16.16.14.mov