Migrate pipeline page visits events to InternalEvents

What does this MR do and why?

Related to #421596 (closed)

Migrate CI/CD page visit events to InternalEvents.

Script used to update the files:

class DebugGenerator < Gitlab::Analytics::InternalEventsGenerator
  source_root File.expand_path('generator_templates/gitlab_internal_events', __dir__)

  def create_metric_file
    validate!

    template "event_definition.yml",
      event_file_path(event),
      options.fetch(:event_desc)
  end
end

[
['p_analytics_ci_cd_pipelines', 'Project level CI CD Analytics pipelines tab has been visited'],
['p_analytics_ci_cd_deployment_frequency', "Project level CI CD Analytics deployment frequency tab has been visited"],
['p_analytics_ci_cd_lead_time', "Project level CI CD Analytics lead time tab has been visited"]
].each do |event_name, event_desc|
  DebugGenerator.new([], {
    event: event_name,
    event_desc: event_desc,
    section: 'dev',
    stage: 'manage',
    group: 'optimize',
    mr: 'https://gitlab.com/gitlab-org/gitlab/-/merge_requests/130854',
    unique: 'user.id'
  }).invoke_all
  ['28d', '7d'].each do |days|
    files = Dir["config/metrics/counts_#{days}/*\_#{event_name}\_*"]
    raise StandardError, "Multiple files found: #{files}" unless files.count == 1
    file_name = files.first

    text = File.read(file_name)
    new_contents = text.gsub(/distribution:/, "events:
  - name: #{event_name}
    unique: user.id\ndistribution:")

    File.open(file_name, "w") {|file| file.puts new_contents }
  end
end

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

1. Set up snowplow-micro
2. Trigger the events migrated here:
   • Visit a project's Analyze -> CI/CD Analytics -> Pipelines
   • Visit a project's Analyze -> CI/CD Analytics -> Deployment frequency and refresh the page
   • Visit a project's Analyze -> CI/CD Analytics -> Lead time and refresh the page
3. Make sure that the events have been triggered with content as per their new event definition files [eg. - category sent as InternalEventTracking] on the http://localhost:9091/micro/good snowplow micro endpoint.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.