Fix module's dependency

[kceiw]

Description

There are a few changes in this PR.

1. Make sure RequiredModules are automatically installed when Az.Tools.Predictor is installed. This is done via clearing the ExternalModuleDependencies. We already set the RequiredModules. Setting ExternalModuleDependencies with the same content confuses PowerShell not to install RequiredModules automatically.
2. Remove the ref assemblies in the output directory and the packages. One of the package we reference contains many assemblies in the content and those assemblies are copied to our output directory. Thus making our package unnecessarily large. We exclude those content files in the packages now.
3. Update the our dependent packages to the stable version.

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)
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  • the markdown help files have been regenerated using the commands listed here