Fix canary user pw creation (#718)

In rare cases the current way of generating a Canary user password in
Cognito can result in a string containing no numerical values, hence
following error is thrown during deployment ( requires
**enable_cw_canaries** config parameter set to True in cdk.json):
`botocore.errorfactory.InvalidPasswordException: An error occurred
(InvalidPasswordException) when calling the AdminCreateUser operation:
Password did not conform with password policy: Password must have
numeric characters`

Changing the password creation to contain at least 1 uppercase and 1
numerical character.


### Feature or Bugfix
- Bugfix


### Detail
- <feature1 or bug1>
- <feature2 or bug2>

### Relates
- <URL or Ticket>

### Security
Please answer the questions below briefly where applicable, or write
`N/A`. Based on
[OWASP 10](https://owasp.org/Top10/en/).

n/a

- Does this PR introduce or modify any input fields or queries - this
includes
fetching data from storage outside the application (e.g. a database, an
S3 bucket)?
  - Is the input sanitized?
- What precautions are you taking before deserializing the data you
consume?
  - Is injection prevented by parametrizing queries?
  - Have you ensured no `eval` or similar functions are used?
- Does this PR introduce any functionality or component that requires
authorization?
- How have you ensured it respects the existing AuthN/AuthZ mechanisms?
  - Are you logging failed auth attempts?
- Are you using or adding any cryptographic features?
  - Do you use a standard proven implementations?
  - Are the used keys controlled by the customer? Where are they stored?
- Are you introducing any new policies/roles/users?
  - Have you used the least-privilege principle? How?


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

deploy/configs/cognito_urls_config.py

@@ -7,6 +7,11 @@
 from botocore.exceptions import ClientError
 
 
+def shuffle_password(pwd):
+    chars = list(pwd)
+    random.shuffle(chars)
+    return ''.join(chars)
+
 def setup_cognito(
     region,
     resource_prefix,
@@ -110,11 +115,15 @@ def setup_cognito(
                         {'Name': 'email', 'Value': f'{username}@amazonaws.com'}
                     ],
                     TemporaryPassword='da@'
-                    + ''.join(
-                        random.SystemRandom().choice(
-                            string.ascii_uppercase + string.digits
+                    + shuffle_password(
+                        random.SystemRandom().choice(string.ascii_uppercase)
+                        + random.SystemRandom().choice(string.digits)
+                        + ''.join(
+                            random.SystemRandom().choice(
+                                string.ascii_uppercase + string.digits
+                            )
+                            for _ in range(11)
                         )
-                        for _ in range(13)
                     ),
                     MessageAction='SUPPRESS',
                 )