Add try/catch functionality (#7221)

# Description

This adds `try` (with an optional `catch` piece). Much like other
languages, `try` will try to run a block. If the block fails to run
successfully, the optional `catch` block will run if it is available.

# User-Facing Changes

This adds the `try` command.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/tests/commands/mod.rs

@@ -82,6 +82,7 @@ mod table;
 mod take;
 mod touch;
 mod transpose;
+mod try_;
 mod uniq;
 mod update;
 mod upsert;

crates/nu-command/tests/commands/try_.rs

@@ -0,0 +1,26 @@
+use nu_test_support::nu;
+use nu_test_support::playground::Playground;
+
+#[test]
+fn try_succeed() {
+    Playground::setup("try_succeed_test", |dirs, _sandbox| {
+        let output = nu!(
+            cwd: dirs.test(),
+            "try { 345 } catch { echo 'hello' }"
+        );
+
+        assert!(output.out.contains("345"));
+    })
+}
+
+#[test]
+fn try_catch() {
+    Playground::setup("try_catch_test", |dirs, _sandbox| {
+        let output = nu!(
+            cwd: dirs.test(),
+            "try { foobarbaz } catch { echo 'hello' }"
+        );
+
+        assert!(output.out.contains("hello"));
+    })
+}