Feat: Next page to accept object

[Mayureshpawar29]

Description

• Added support for JSON object configurations in the nextPage field for pagination. Previously, nextPage only supported string URLs. Now it can also accept a JSON object with endpoint, method, body, and headers fields.

• Many APIs require POST requests with dynamic request bodies for pagination.
  The old string-only approach couldn't handle these cases.
  Before (only strings worked):
  nextPage: '.data | "https://api.example.com/page2"'
  After (strings AND objects work):

# Still works - strings
nextPage: '.data | "https://api.example.com/page2"'

# NEW - objects for complex pagination
nextPage: |
  .data | fromjson | {
    endpoint: "https://api.example.com/graphql",
    method: "POST",
    body: ({query: "...", variables: {after: .cursor}} | tojson),
    headers: {"Authorization": "Bearer token"}
  }

• Fully backwards compatible - existing string-based configs still work

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation and I have updated the documentation accordingly.
• I have added tests to cover my changes.
• I have checked downstream dependencies (e.g. ExternalTaskSensors) by searching for DAG name elsewhere in the repo

[hladush]

why do you need it?

[Mayureshpawar29]

Just to be safe - if something other than a string or object is passed to nextPage (like a boolean, null, number, array, or anything else), we break the pagination loop instead of continuing with invalid data.

[hladush]

I like feature