Add blocks and blocksAsString to filesUploadV2

[lytt925]

In the API document for files.completeUploadExternal the field blocks is accepted but it cannot be added in the FilesUploadV2Request in the current slack-api-client.

I have done some changes in my fork

Category (place an x in each of the [ ])

• [ ] bolt (Bolt for Java)
• [ ] bolt-{sub modules} (Bolt for Java - optional modules)
• [x] slack-api-client (Slack API Clients)
• [ ] slack-api-model (Slack API Data Models)
• [ ] slack-api-*-kotlin-extension (Kotlin Extensions for Slack API Clients)
• [ ] slack-app-backend (The primitive layer of Bolt for Java)

Requirements

Please make sure if this topic is specific to this SDK. For general questions/issues about Slack API platform or its server-side, could you submit questions at https://my.slack.com/help/requests/new instead. :bow:

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[WilliamBergamin]

Thanks for bringing this up @lytt925 we will address this in our next release 💯

[github-actions[bot]]

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