[ci no changelog needed]
This PR reverts commit [0836ce741d](0836ce741d) because of the spotted regression:
To reproduce:
1. Open a default project.
2. Without doing anything else, cmd + click on any node to edit it.
3. Abort editing by pressing escape.
4. Top-most node disappears (it is actually removed from scene)
If you start editing the bottom node - you will also see a visible regression in node searcher's position.
See thread https://discord.com/channels/401396655599124480/950730235719065620/950731247909478410 for details.
API for storing metadata.
See: https://www.pivotaltracker.com/story/show/181149277
# Important Notes
**New APIs**:
- Storing metadata is implemented with `profiler::MetadataLogger`.
- A full metadata storage/retrieval example is in [the top-level doctests](https://github.com/enso-org/enso/blob/wip/kw/profiling-metadata-api/lib/rust/profiler/data/src/lib.rs) for profiler::data, a crate which implements an API for profiling data consumers (it abstracts away the low-level details of the event log, and checks its invariants in the process) [after review of this new API here I'll open a PR to add it to the design doc].
**Implementation**:
- `profiler::Event` is parameterized by a metadata type, so that different types of metadata can be dependency-injected into it.
- A data consumer defines its metadata type as an enum of all the kinds of metadata it is interested in.
- Producing the metadata enum is accomplished without defining its type (which would require dependencies from around the app): A `MetadataLogger` internally use a serialization helper `Variant` to serialize its variant of the metadata enum without knowledge of the other possible variants.
**Performance impact**: still in the low ns/measurement range, comparable to pushing to a vec.
*Note*: `LocalVecBuilder` is currently present under the name `Log`, which is accurate but probably too overloaded. I'd like to find the right name for it, document it with examples, and move it to its own crate under data-structures, but I don't want doing that to hold up this PR.
[The Task](https://www.pivotaltracker.com/story/show/180887253)
A new (+) button on the left-bottom corner appeared. It may be clicked to open searcher in the middle of the scene, as an alternative to tab key.
https://user-images.githubusercontent.com/3919101/154514279-7972ed6a-0203-47cb-9a09-82dba948cf2f.mp4
# Important Notes
* The window_control_buttons::common was extracted to separate crate `ensogl-component-button` almost without change.
* This includes a severe refactoring of adding nodes in general in the Graph Editor. The whole responsibility of adding new nodes (and starting their editing) was moved to Graph Editor - the Project View only reacts for GE events to show searcher properly.
* The status bar was moved from the bottom-left corner to the middle-top of the scene. It does not collide with (+) button, and plays "notification" role anyway.
* The `interface` debug scene was buggy. The problem was with one expression's span-tree. When I replaced it, the scene works.
* I've removed "new searcher" API, as it is completely outdated.
* I've changed code owners of integration tests to GUI team, as it is the team writing mostly the integration tests (int rust)
