feat(contacts): import dss plugin for search and cloud contact resolution

[sreenara]

COMPLETES #NA

This pull request addresses

calling plugin missing dss plugin import due to which we can't utilize dss functions in the calling code.

by making the following changes

requiring the @webex/internal-plugin-dss in calling.js

Change Type

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Tooling change
• Internal code refactor

The following scenarios where tested

1. Check the presence of the webex.internal.dss object.
2. Run a test to lookup a user by doing contacts.webex.internal.dss.lookup({id: userId});
3. Test other calling functionality like making calls.

I certified that

• I have read and followed contributing guidelines

• I discussed changes with code owners prior to submitting this pull request

• I have not skipped any automated checks

• All existing and new tests passed

• I have updated the documentation accordingly

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