Add basic bash and Python tasks (#10548)

Part of https://github.com/zed-industries/zed/issues/5141

* adds "run selection" and "run file" tasks for bash and Python.
* replaces newlines with `\n` symbols in the human-readable task labels
* properly escapes task command arguments when spawning the task in
terminal

Caveats:

* bash tasks will always use user's default shell to spawn the
selections, but they should rather respect the shebang line even if it's
not selected
* Python tasks will always use `python3` to spawn its tasks now, as
there's no proper mechanism in Zed to deal with different Python
executables

Release Notes:

- Added tasks for bash and Python to execute selections and open files
in terminal

crates/project/src/terminals.rs

@@ -44,6 +44,7 @@ impl Project {
             .unwrap_or_else(|| Path::new(""));
 
         let (spawn_task, shell) = if let Some(spawn_task) = spawn_task {
+            log::debug!("Spawning task: {spawn_task:?}");
             env.extend(spawn_task.env);
             // Activate minimal Python virtual environment
             if let Some(python_settings) = &python_settings.as_option() {