feat: Added support for CQA with unit tests.

[Arsh-Kashyap]

#minor

Description

Added Language Service utils for querying Language Service via bot. DefaultAnswer can be configured from secrets file. Updated unit tests and added tests for CQA(Custom Question Answering).

How to test

1. Use this PR for samples.
2. Run yarn and yarn build in root folder of SDK.
3. Run yarn build in botbuilder-ai and botbuilder-dialogs in SDK.
4. Run yarn link in botbuilder-dialogs in sdk.
5. Run yarn link botbuilder-dialogs in botbuilder-ai. Then run yarn link.
6. Go to samples and run npm install , yarn link botbuilder-ai and yarn link botbuilder-dialogs in 48.customQABot-all-features.
7. Run npm start to test.
8. Same steps can be performed to test 12.customQABot, and previous samples 11.qnamaker and 49.qnamaker-all-features.

Specific Changes

Added Language Service utils for querying Language Service via bot.

Default Answer can now be configured from .env file in nodejs sample.

If Default Answer is not mentioned it will render the one filled in language studio.

Testing

Added Language Service tests and updated existing tests.

[mrivera-ms]

@Arsh-Kashyap, please add code coverage to qnaCardBuilder.ts, generateAnswerUtil.ts and languageServiceUtil.ts. Particularly qnaCardBuilder.ts which is dropping to 38.71%:

Before:

After:

[coveralls]

Pull Request Test Coverage Report for Build 2106661739

• 197 of 215 (91.63%) changed or added relevant lines in 11 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 84.502%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botbuilder-ai/src/qnaCardBuilder.ts	13	14	92.86%
libraries/botbuilder-ai/src/qnamaker-utils/generateAnswerUtils.ts	10	11	90.91%
libraries/botbuilder-ai/src/customQuestionAnswering.ts	56	59	94.92%
libraries/botbuilder-ai/src/qnamaker-utils/languageServiceUtils.ts	51	55	92.73%
libraries/botbuilder-ai/src/qnaMakerDialog.ts	52	61	85.25%

Totals
Change from base Build 2031580169:	0.01%
Covered Lines:	19907
Relevant Lines:	22312

---

💛 - Coveralls

[mrivera-ms]

Thanks for the latest changes, @Arsh-Kashyap. I have resolved the comments that have been fixed since the previous review. A few issues:

• The sample 48.customQABot-all-features does not run as is. Perhaps the sample (which is in Draft), is not updated?
• After fixing the errors in the sample, testing as indicated in the description throws errors because there are modules in botbuilder-ai that are not found. Please make sure to add the corresponding exports for your new types.
• The code coverage of qnaCardBuilder that I mentioned in the previous iteration has gone down.

cc @sahithimurty @gabog @tracyboehrer