When nodes get invalidated in the cache, they have to be recomputed. Let the IDE know which of the nodes are pending by sending `Api.ExpressionUpdate.Payload.Pending` message.
# Important Notes
This PR introduces new `Api.ExpressionUpdate.Payload.Pending` message. This message is delivered before re-computation of nodes. Later `Api.ExpressionUpdate.Payload.Value` or other is sent to notify the IDE that a value for given node is available.
Trivial implementation of of the `Api.ExpressionUpdate.Payload.Pending` message in the IDE is provided by this PR to (improperly) visualize pending node status - further improvements needed in follow up PRs.
This change adds Autosave action for open buffers. The action is scheduled
after every edit request and is cancelled by every explicit save file request, if
necessary. Successful autosave also notifies any active clients of the buffer.
Related to https://www.pivotaltracker.com/story/show/182721656
# Important Notes
WIP
PR allows to attach metod pointers as a visualization expressions. This way it allows to attach a runtime instrument that enables caching of intermediate expressions.
# Important Notes
ℹ️ API is backward compatible.
To attach the visualization with caching support, the same `executionContext/attachVisualisation` method is used, but `VisualisationConfig` message should contain the message pointer.
While `VisualisationConfiguration` message has changed, the language server accepts both new and old formats to keep visualisations working in IDE.
#### Old format
```json
{
"executionContextId": "UUID",
"visualisationModule": "local.Unnamed.Main",
"expression": "x -> x.to_text"
}
```
#### New format
```json
{
"executionContextId": "UUID",
"expression": {
"module": "local.Unnamed.Main",
"definedOnType": "local.Unnamed.Main",
"name": "encode"
}
}
```
Show custom icons in Component Browser for entries that have a non-empty `Icon` section in their docs with the section's body containing a name of a predefined icon.
https://www.pivotaltracker.com/story/show/182584336
#### Visuals
A screenshot of a couple custom icons in the Component Browser:
<img width="346" alt="Screenshot 2022-07-27 at 15 55 33" src="https://user-images.githubusercontent.com/273837/181265249-d57f861f-8095-4933-9ef6-e62644e11da3.png">
# Important Notes
- The PR assigns icon names to four items in the standard library, but only three of them are shown in the Component Browser because of [a parsing bug in the Engine](https://www.pivotaltracker.com/story/show/182781673).
- Icon names are assigned only to four items in the standard library because only two currently predefined icons match entries in the currently defined Virtual Component Groups. Adjusting the definitions of icons and Virtual Component Groups is covered by [a different task](https://www.pivotaltracker.com/story/show/182584311).
- A bug in the documentation of the Enso protocol message `DocSection` is fixed. A `text` field in the `Tag` interface is renamed to `body` (this is the field name used in Engine).
Changelog:
- Describe the `EditKind` optional parameter that allows enabling engine-side optimizations, like value updates
- Describe the `text/openBuffer` message required for the lazy visualizations feature
Changelog:
- add: component groups to package descriptions
- add: `executionContext/getComponentGroups` method that returns component groups of libraries that are currently loaded
- doc: cleanup unimplemented undo/redo commands
- refactor: internal component groups datatype