Refactors components into a main `<search-box>` element

* 73 - Graph allow user to toggle some features in settings

* Modified name of "enableGhostRefs" property to be "showGhostRefsOnRowHover" instead

Adds search shortcuts F3/Cmd+G to the graph

Handles timeout of pending completion calls

Renames more to hasMore

- clears search results when invalid
- hides search when gated

Adds keyboard shortcuts for next/prev search
Adds timeout for webview completion events

Adds search cancellation to avoid needless calls
Adds search limit setting for the Graph

Adds error highlight for no results like vscode
Removes clear search button (styling looks bad)

- adds check to ensure commit is in graph
- moves input value validation to input handler
- removes mock state

Updates on configuration changes

Changes `sendCommandWithCompletion` to return a promise