port: [#6813][#6798] Not able to create instance of BlobsTranscriptStore using TokenCredential instead of connectionString and containerName

[JhontSouth]

Fixes #4715

Description

This PR allows the use of Token Credentials to authenticate and create an instance of BlobsTranscriptStore.

Specific Changes

• Added parameters blobServiceUri and tokenCredential in BlobsTranscriptStore constructors.
• Added constructor validations in unit tests.

Testing

The following images show the bot working and saving transcripts using BlobsTranscriptStore instantiated with token credentials.

[coveralls]

Pull Request Test Coverage Report for Build 10114846031

Details

• 11 of 14 (78.57%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.02%) to 84.417%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botbuilder-azure-blobs/src/blobsTranscriptStore.ts	11	14	78.57%

Totals
Change from base Build 10112673859:	-0.02%
Covered Lines:	20435
Relevant Lines:	22913

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💛 - Coveralls