port: [#6432] TeamsInfo.GetMemberAsync(...) doesn't work properly in Skill Bot scenario, it returns http 405 error (#6443)

[ceciliaavila]

Fixes #4317

Description

This PR ports the changes in PR#6443 to fix the error thrown when executing the TeamsInfo.GetMember in a root-skill scenario.

Specific Changes

• Added the handleGetConversationMember and onGetConversationMember methods in ChannelServiceHandlerBase.
• Added the processGetConversationMember method in channelServiceRoutes.
• Added the onGetConversationMember method in the CloudSkillHandler class.
• Added the implementation of the onGetMember method in the SkillHandlerImpl class.
• Added the cloudSkillHandler.test.js file with unit test for CloudSkillHandler constructor and onGetConversationMember methods.

Testing

These images show the skill bot retrieving the member's information successfully and the new unit test passing.

[coveralls]

Pull Request Test Coverage Report for Build 3265595790

• 2 of 18 (11.11%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.004%) to 84.61%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botbuilder/src/channelServiceHandlerBase.ts	0	3	0.0%
libraries/botbuilder/src/skills/skillHandlerImpl.ts	0	6	0.0%
libraries/botbuilder/src/channelServiceRoutes.ts	1	8	12.5%

Files with Coverage Reduction	New Missed Lines	%
libraries/botbuilder-lg/src/templateExtensions.ts	1	84.48%

Totals
Change from base Build 3206725406:	-0.004%
Covered Lines:	19936
Relevant Lines:	22326

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💛 - Coveralls