Fix MR analytics dashboard table pagination

What does this MR do and why?

Fixes some pagination issues that were visible in the MR analytics dashboard throughput table.

Changes

• Removes default page config inherited from the legacy MR analytics app
• When clicking next/prev page from the DataTable, make sure to include the page size (first or last)
• DataTable pagination now uses the same nomenclature as our GraphQL API (startCursor/endCursor instead of prevPageCursor/nextPageCursor)
• Restrict table to 20 rows and match the visualization height as well

References

Screenshots or screen recordings

Note: Example limited to 4 rows as opposed to the expected 20

Screen_Recording_2025-09-04_at_2.11.25_PM

How to set up and validate locally

• Enable consolidate_mr_analytics_in_shared_dashboards feature flag
• Create test MRs for a project of your choice

project = Project.find(PROJECT_ID)

# Set the dates
created_date = 1.week.ago
merged_date = 1.day.ago

# Create 100 closed MRs with specific dates
100.times do |i|
  source_branch = "feature-branch-#{i}"
  # Create a branch
  project.repository.create_branch(source_branch, 'master') # Use your default branch name here

  # Create MR with created_at set to 1 week ago
  mr = MergeRequest.new(
    title: "Test MR #{i}",
    source_project: project,
    target_project: project,
    source_branch: source_branch,
    target_branch: 'master',
    author: User.first
  )

  # Set created_at to 1 week ago
  mr.created_at = created_date
  mr.save!

  # Merge the MR with merged_at set to yesterday
  mr.mark_as_merged
  mr.metrics.update!(merged_at: merged_date)

  puts "Created MR #{i}"
end

• Navigate to the MR analytics dashboard for your project and verify that the table pagination works as expected (http://gdk.test:3000/flightjs/Flight/-/analytics/dashboards/merge_request_analytics)

MR acceptance checklist

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Related to #542327 (closed)