Give warning if user inputs not encrypted password to user module (#43615)

* Check the password format

Check the password format and notify user if they
input unencrypted password.

* Fix sanity error

* Add integration test

* Missed a task name

* Hard code the testing password

Since some testing platfrom has no passlib installed

* Add changelog fragment

* Rework some English sentences

* Fix a grammar mistake

test/integration/targets/user/tasks/main.yml

@@ -64,6 +64,46 @@
       - user_test0_1 is not changed
       - '"ansibulluser" in user_names.stdout_lines'
 
+# test user add with password
+- name: add an encrypted password for user
+  user:
+    name: ansibulluser
+    password: "$6$rounds=656000$TT4O7jz2M57npccl$33LF6FcUMSW11qrESXL1HX0BS.bsiT6aenFLLiVpsQh6hDtI9pJh5iY7x8J7ePkN4fP8hmElidHXaeD51pbGS."
+    state: present
+    update_password: always
+  register: test_user_encrypt0
+
+- name: there should not be warnings
+  assert:
+    that: "'warnings' not in test_user_encrypt0"
+
+- block:
+    - name: add an plaintext password for user
+      user:
+        name: ansibulluser
+        password: "plaintextpassword"
+        state: present
+        update_password: always
+      register: test_user_encrypt1
+
+    - name: there should be a warning complains that the password is plaintext
+      assert:
+        that: "'warnings' in test_user_encrypt1"
+
+    - name: add an invalid hashed password
+      user:
+        name: ansibulluser
+        password: "$6$rounds=656000$tgK3gYTyRLUmhyv2$lAFrYUQwn7E6VsjPOwQwoSx30lmpiU9r/E0Al7tzKrR9mkodcMEZGe9OXD0H/clOn6qdsUnaL4zefy5fG+++++"
+        state: present
+        update_password: always
+      register: test_user_encrypt2
+
+    - name: there should be a warning complains about the character set of password
+      assert:
+        that: "'warnings' in test_user_encrypt2"
+  when: ansible_system != 'Darwin'
+
+
 # https://github.com/ansible/ansible/issues/42484
 # Skipping macOS for now since there is a bug when changing home directory
 - block: