Add index to chat names table on team_id and chat_id

What does this MR do and why?

This MR adds an index on chat_names table on team_id and chat_id.

It stemmed from a discussion at !103478 (comment 1173507962)

Migrations

UP

main: == 20221116113323 AddIndexOnTeamIdAndChatId: migrating ========================
main: -- transaction_open?()
main:    -> 0.0000s
main: -- view_exists?(:postgres_partitions)
main:    -> 0.0079s
main: -- index_exists?(:chat_names, [:team_id, :chat_id], {:name=>"index_chat_names_on_team_id_and_chat_id", :algorithm=>:concurrently})
main:    -> 0.0022s
main: -- execute("SET statement_timeout TO 0")
main:    -> 0.0001s
main: -- add_index(:chat_names, [:team_id, :chat_id], {:name=>"index_chat_names_on_team_id_and_chat_id", :algorithm=>:concurrently})
main:    -> 0.2584s
main: -- execute("RESET statement_timeout")
main:    -> 0.0005s
main: == 20221116113323 AddIndexOnTeamIdAndChatId: migrated (0.2818s) ===============

Down

main: == 20221116113323 AddIndexOnTeamIdAndChatId: reverting ========================
main: -- transaction_open?()
main:    -> 0.0000s
main: -- view_exists?(:postgres_partitions)
main:    -> 0.0018s
main: -- indexes(:chat_names)
main:    -> 0.0022s
main: -- execute("SET statement_timeout TO 0")
main:    -> 0.0001s
main: -- remove_index(:chat_names, {:algorithm=>:concurrently, :name=>"index_chat_names_on_team_id_and_chat_id"})
main:    -> 0.0018s
main: -- execute("RESET statement_timeout")
main:    -> 0.0001s
main: == 20221116113323 AddIndexOnTeamIdAndChatId: reverted (0.0126s) ===============

How to set up and validate locally

1. Migration should run without any issues.

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 #344856 (closed)