Add ability to copy a permalink to a line (#7119)

This PR adds the ability to copy the permalink to a line from within
Zed.

This functionality is available through the `editor: copy permalink to
line` action in the command palette:

<img width="589" alt="Screenshot 2024-01-30 at 7 07 46 PM"
src="https://github.com/zed-industries/zed/assets/1486634/332282cb-211f-4f16-9eb1-415bcfee9b7b">

Executing this action will create a permalink to the currently selected
line(s) and copy it to the clipboard.

Here is an example line:

```
56c80e8011/src/lib.rs (L25)
```

Currently, both GitHub and GitLab are supported.

### Notes and known limitations

- In order to determine where to permalink to, we read the URL of the
`origin` remote in Git. This feature will not work if the `origin`
remote is not present.
- Attempting to permalink to a ref that is not pushed to the origin will
result in the link 404ing.
- Attempting to permalink when Git is in a dirty state may not generate
the right link.
- For instance, modifying a file (e.g., adding new lines) and grabbing a
permalink to it will result in incorrect line numbers.

Release Notes:

- Added the ability to copy a permalink to a line
([#6777](https://github.com/zed-industries/zed/issues/6777)).
- Available via the `editor: copy permalink to line` action in the
command palette.

crates/zed/Cargo.toml

@@ -148,7 +148,7 @@ tree-sitter-vue.workspace = true
 tree-sitter-uiua.workspace = true
 tree-sitter-zig.workspace = true
 
-url = "2.2"
+url.workspace = true
 urlencoding = "2.1.2"
 uuid.workspace = true