Move Error logic out of botbuilder into authentication layer

[Zerryth]

Fixes #1445

Description

See discussion in comment.

• Create custom error class that throws richer errors, so we do not have to rely on parsing the error message to determine the correct status code.
• Move the logic out of botbuilder into the authentication layer

Specific Changes

• Create IStatusCodeError in botbuilder-schema.
  • Currently there's a custom StatusCodeError class built in botbuilder, however we can't use it in the auth layers in botframework-connector
  • This dependency would break browser compatibility and would be a circular dependency
  • Alternatively moving into botframework-schema breaks backwards compatibility
• Created AuthenticationError class (ctor needs status code and message) in botframework-connector
  • Auth layers that activate when BotFrameworkAdapter.authenticateConnection() is called now throw this custom error, so we rely less heavily on string-parsing to determine status code to throw. (Throwing errors w/status code already done in other parts of SDK as well):.
    • JwtTokenValidation
    • Channel Validation classes: ChannelValidation, EmulatorValidation, GovernmentChannelValidation, SkillValidation
    • JwtTokenExtractor
    • EndorsementsValidation
• Made helper functions to determine auth code if the Adapter catches an error that does not have a status code, as fallback
  • (such as errors thrown from 3rd party libraries like jsonwebtoken that handles validating tokens with Channel Service's asymmetical signatures)
  • Note: TypeScript doesn't allow you to catch errors of a specific type 😭

[coveralls]

Pull Request Test Coverage Report for Build 123154

• 72 of 90 (80.0%) changed or added relevant lines in 13 files are covered.
• 9 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.03%) to 77.544%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botframework-connector/src/auth/channelValidation.ts	5	6	83.33%
libraries/botframework-connector/src/auth/enterpriseChannelValidation.ts	6	7	85.71%
libraries/botbuilder/src/botFrameworkAdapter.ts	6	8	75.0%
libraries/botframework-connector/src/auth/governmentChannelValidation.ts	5	7	71.43%
libraries/botframework-connector/src/auth/openIdMetadata.ts	2	4	50.0%
libraries/botframework-connector/src/auth/jwtTokenExtractor.ts	2	6	33.33%
libraries/botframework-connector/src/auth/emulatorValidation.ts	3	9	33.33%

Files with Coverage Reduction	New Missed Lines	%
libraries/botframework-streaming/src/webSocket/webSocketTransport.ts	2	80.65%
libraries/botframework-streaming/src/webSocket/webSocketServer.ts	7	66.67%

Totals
Change from base Build 123152:	-0.03%
Covered Lines:	11976
Relevant Lines:	14717

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💛 - Coveralls

[Stevenic]

[Zerryth]

Hmm, chrome tests are breaking in the build, and I don't believe it has anything to do with the PR changes...reached out to Bruce regarding that aspect. (UPDATE: seems like browser test breaks are a known issue, with Steven on getting the fix)

Thanks @Stevenic for reviewing! (Woohoo a PR review finally 😄)
@carlosscastro Steve took a look at the PR, but said that it'd be best if you looked into too before merging though, please

[Zerryth]

@stevengum @carlosscastro

• Changed status codes thrown with the AuthenticationErrors pointed out
• AuthenticationError unit tests are now separated into authenticationError.test.js
• Replaced inexplicit numbers in unit tests with StatusCodes enum values instead

LMK if anything else is needed 😀