Add changelog of new added module

[dingmeng-xue]

Description

Previously, changelog and release note only come from the module in released version of Az. When we add a new module to Az, script skip this new module because it is not included in released Az.

This change uses module list of local Az instead of remote Az. It shows "found new module" when module name is in local Az but not in remote Az. Then, new added module is added into updatedModules.

Adding new module to Az only is considered as minor release of Az.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
    • {Please put the link here}
  • the markdown help files have been regenerated using the commands listed here