Add users authentication routes

matrixgw_backend/src/utils/rand_utils.rs

@@ -0,0 +1,6 @@
+use rand::distr::{Alphanumeric, SampleString};
+
+/// Generate a random string of a given length
+pub fn rand_string(len: usize) -> String {
+    Alphanumeric.sample_string(&mut rand::rng(), len)
+}