[Project] Save & restore named graph bookmarks

Add a way to recall previously saved graph bookmarks.

## Goals

- Save a bookmark of the current graph
- Restore a graph bookmark
- Name a graph bookmark

## Potential Issues

- Node and edge IDs may no longer exist since graph bookmark was saved
- Connection may have changed since graph bookmark was saved
- Cascade of database queries may be taxing on the server

## Prerequisites

- #587

## UX Ideas

- New sidebar with list of saved graph bookmark
- Show count of nodes and edges
- Show date of snapshot
- Show date of last recall
- Allow custom name (default to date and time)
- Add tabs to the connection detail view: Data Explorer & Saved Graphs
- Available actions on saved graphs:
- Reload
- Rename
- Delete
- Sort list by most recently loaded
- Persist list of timestamps of when the bookmark was loaded
- This allows sorting by a weighted frequency of use
- Allow one undo after loading a bookmark or clearing the graph
- Store the previous graph in memory
- Replace previous graph with current graph on load of a graph bookmark

### Mockup

This is a rough Markdown style mock up of an individual saved graph item. This would exist in a list in the sidebar.

> **Jun 6, 4:53 pm**
> 34 nodes • 16 edges
>
> [**...**] [**Reload**]

## Tasks

- [ ] [Task] Add function to create graph bookmark
- [ ] [Task] Add function to delete graph bookmark
- [ ] [Task] Add function to restore graph bookmark
- [ ] [Task] Add function to rename graph bookmark
- [ ] [Task] Add new graph bookmark sidebar
- [ ] [Task] Add graph bookmarks tab to connection details
- [ ] [Task] Add temporary undo after loading graph bookmark