[Vis Builder] Save Visualization

[ashwin-pc]

Add the ability to save and restore a visualization using the drag and drop editor

Tasks

Saving

• [D&D] Ensure relationships to index patterns are saved correctly #1878
• [D&D] Make new "meta" state slice to keep track of things we don't want to save and load #1879
• [Vis Builder] Complete unhappy save paths (error handling flows) #1880

Loading

• [D&D] Handle routing for loading and updating a saved viz #1868
• [D&D] Sync state with saved object #1867
• [Vis Builder] Add validation steps between serialization/deserialization and state sync #1881
• [D&D] Complete unhappy load paths (error handling flows) #1882
• [D&D] Add saved d&d visualizations to the visualization list #1887

Management

• [D&D] Enable "Inspect" action from saved objects management plugin #1817
• [Vis Builder] Create icon for saved object to represent Vis Builder / differentiate from other visualizations oui#613

Testing

• [Vis Builder] Functional: create visualization, save it, go to save object management, inspect, make change and save, navigate to edit view, make change and save #1884
• [D&D] Functional: validate export/import of saved objects #1885