chore: Extract languages from zed crate (#8270)

- Moves languages module from `zed` into a separate crate. That way we
have less of a long pole at the end of compilation.
- Removes moot dependencies on editor/picker. This is totally harmless
and might help in the future if we decide to decouple picker from
editor.

Before:
```
Number of crates that depend on 'picker' but not on 'editor': 1
Total number of crates that depend on 'picker': 13
Total number of crates that depend on 'editor': 30
```
After:
```
Number of crates that depend on 'picker' but not on 'editor': 5
Total number of crates that depend on 'picker': 12
Total number of crates that depend on 'editor': 26
```
The more crates depend on just picker but not editor, the better in that
case.

Release Notes:

- N/A

crates/recent_projects/Cargo.toml

@@ -10,7 +10,6 @@ path = "src/recent_projects.rs"
 doctest = false
 
 [dependencies]
-editor.workspace = true
 futures.workspace = true
 fuzzy.workspace = true
 gpui.workspace = true
@@ -26,6 +25,3 @@ theme.workspace = true
 ui.workspace = true
 util.workspace = true
 workspace.workspace = true
-
-[dev-dependencies]
-editor = { workspace = true, features = ["test-support"] }