Add a workflow step resolution view (#16315)

You can now click on a step header (the words `Step 3`, etc) to open a
new tab containing a dedicated view for the resolution of that step.
This view looks similar to a context editor, and has sections for the
step input, the streaming tool output, and the interpreted results.

Hitting `cmd-enter` in this view re-resolves the step.


https://github.com/user-attachments/assets/64d82cdb-e70f-4204-8697-b30df5a645d5



Release Notes:

- N/A

---------

Co-authored-by: Nathan <nathan@zed.dev>

crates/language/src/language.rs

@@ -71,7 +71,7 @@ pub use language_registry::{
     PendingLanguageServer, QUERY_FILENAME_PREFIXES,
 };
 pub use lsp::LanguageServerId;
-pub use outline::{render_item, Outline, OutlineItem};
+pub use outline::*;
 pub use syntax_map::{OwnedSyntaxLayer, SyntaxLayer};
 pub use text::{AnchorRangeExt, LineEnding};
 pub use tree_sitter::{Node, Parser, Tree, TreeCursor};