Support async constraint validation for first list partition

What does this MR do and why?

See #393395 (closed). This is a MR to provide helpers to set the partition check constraint for new records and validate the constraint during weekend.

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How to set up and validate locally

• create a test table in rails dbconsole for both gitlabhq_development and gitlabhq_development_ci:

  CREATE TABLE public.test_partitions (
      id bigint NOT NULL,
      partition_id bigint DEFAULT 100 NOT NULL
  );
  ALTER TABLE ONLY public.test_partitions
      ADD CONSTRAINT test_partitions_pkey PRIMARY KEY (id, partition_id);

• run

  rails g migration test_partition_constraint_validation

• edit the migration file

  class TestPartitionConstraintValidation < Gitlab::Database::Migration[2.1]
    include Gitlab::Database::PartitioningMigrationHelpers::TableManagementHelpers
  
    disable_ddl_transaction!
  
    def up
      prepare_constraint_for_list_partitioning(
        table_name: :test_partitions,
        partitioning_column: :partition_id,
        parent_table_name: :p_test_partitions,
        initial_partitioning_value: 100,
        async: true
      )
    end
  
    def down
      # do nothing
    end
  end

• run the migration

  rails db:migrate

• check if the table has the partition constraint in Rails dbconsole:

  \d public.test_partitions;

• check if the async partition constraint validation is created in Rails console:

  Gitlab::Database::AsyncConstraints::PostgresAsyncConstraintValidation.check_constraint_type.last

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.

Related to #393395 (closed)