AWS::DirectoryService::MicrosoftAD - Remove Password and Initialize with a Random Value

The current situation is a disaster:

- I'm forced to provide a password
- I cannot rotate the password through CloudFormation without triggering replacement
- If I rotate the password in the UI (as instructed), I have to keep track of the original password in the event I need to make **any** other update to the stack (otherwise I trigger a replacement). Where am I supposed to keep that password?

I believe this attribute should be deprecated and removed. Directory Services should be initialized with a random password and users should reset the password through the UI (or a different API).

## 6. Category (required) - Will help with tagging and be easier to find by other users to +1

Security, Identity, & Compliance

Start by reviewing the AWS::DirectoryService::MicrosoftAD resource behavior described in the issue, especially password initialization, rotation, and replacement. Done would mean the resource can initialize with a random password and subsequent password changes do not require retaining the original value or trigger replacement.

Written by the indexing model from the issue text.