[2] Convert webhook handlers to Typescript

[MrOrz]

This will make future modification to context & payloads easier.

• Type choosingArticle, choosingReply, askingArticleSource and askingArticleSubmissionConsent
• refactor(webhook): Read / write of postback data is protected by type
• fix(chatbotState): replace PostbackEvent with actual type used in handlers
• Remove unused issuedAt field
• Introduces ts-reset for [].filter & JSON.parse types that makes sense.
• refactor(gql): narrow the type of GraphQL response

[coveralls]

Pull Request Test Coverage Report for Build 6535987939

• 38 of 39 (97.44%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.4%) to 90.012%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/webhook/handlers/askingArticleSubmissionConsent.ts	9	10	90.0%

Totals
Change from base Build 6535983227:	-0.4%
Covered Lines:	1000
Relevant Lines:	1075

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💛 - Coveralls

[MrOrz]

Current dependencies on/for this PR:

• master
  • PR [1] Cleanup unused field, fix and define action payload type #366
    • PR [2] Convert webhook handlers to Typescript #365 👈
      • PR [3] remove selectedArticleText and selectedReplyId from context #368

This comment was auto-generated by Graphite.

[MrOrz]

Merge activity

• Oct 18, 2:04 PM: @MrOrz started a stack merge that includes this pull request via Graphite.
• Oct 18, 2:04 PM: @MrOrz merged this pull request with Graphite.