oeqa: add "maturin develop" SDK test case

'maturin develop' first checks that a virtual environment
has been created, which is a good test for our python3 SDK
environment ;)

Source for guessing-game lifted from https://www.maturin.rs/tutorial

The test case is expected to fetch any necessary crates, build a
development version of the crate and package it as a wheel

Needs at a minimum the following in e.g. local.conf:
TOOLCHAIN_HOST_TASK:append = " nativesdk-python3-maturin"
SDK_INCLUDE_TOOLCHAIN = '1'
SDK_TOOLCHAIN_LANGS += 'rust'

The output of 'maturin develop' should be something like:
...
🔗 Found pyo3 bindings with abi3 support for Python ≥ 3.8
🐍 Not using a specific python interpreter
📡 Using build options features from pyproject.toml
   ...
   Compiling guessing-game v0.1.0 (/path/to/guessing-game)
    Finished dev [unoptimized + debuginfo] target(s) in 7.14s
📦 Built wheel for abi3 Python ≥ 3.8 to /path/to/tmpdir/guessing_game-0.1.0-cp38-abi3-linux_x86_64.whl
🛠 Installed guessing-game-0.1.0

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 48 insertions, 0 deletions

diff --git a/meta/lib/oeqa/files/maturin/guessing-game/src/lib.rs b/meta/lib/oeqa/files/maturin/guessing-game/src/lib.rs
new file mode 100644
index 0000000000..6828466ed1
--- /dev/null
+++ b/meta/lib/oeqa/files/maturin/guessing-game/src/lib.rs
@@ -0,0 +1,48 @@
+use pyo3::prelude::*;
+use rand::Rng;
+use std::cmp::Ordering;
+use std::io;
+
+#[pyfunction]
+fn guess_the_number() {
+    println!("Guess the number!");
+
+    let secret_number = rand::thread_rng().gen_range(1..101);
+
+    loop {
+        println!("Please input your guess.");
+
+        let mut guess = String::new();
+
+        io::stdin()
+            .read_line(&mut guess)
+            .expect("Failed to read line");
+
+        let guess: u32 = match guess.trim().parse() {
+            Ok(num) => num,
+            Err(_) => continue,
+        };
+
+        println!("You guessed: {}", guess);
+
+        match guess.cmp(&secret_number) {
+            Ordering::Less => println!("Too small!"),
+            Ordering::Greater => println!("Too big!"),
+            Ordering::Equal => {
+                println!("You win!");
+                break;
+            }
+        }
+    }
+}
+
+/// A Python module implemented in Rust. The name of this function must match
+/// the `lib.name` setting in the `Cargo.toml`, else Python will not be able to
+/// import the module.
+#[pymodule]
+fn guessing_game(_py: Python, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(guess_the_number, m)?)?;
+
+    Ok(())
+}
+