Simplify debug launcher UI (#31928)

This PR updates the name of the `NewSessionModal` to `NewProcessModal`
(to reflect it's new purpose), changes the tabs in the modal to read
`Run | Debug | Attach | Launch` and changes the associated types in code
to match the tabs. In addition, this PR adds a few labels to the text
fields in the `Launch` tab, and adds a link to open the associated
settings file. In both debug.json files, added links to the zed.dev
debugger docs.

Release Notes:

- Debugger Beta: Improve the new process modal

crates/debugger_ui/Cargo.toml

@@ -50,6 +50,7 @@ project.workspace = true
 rpc.workspace = true
 serde.workspace = true
 serde_json.workspace = true
+# serde_json_lenient.workspace = true
 settings.workspace = true
 shlex.workspace = true
 sysinfo.workspace = true