cli: PGSERVICEFILE behaves differently between cockroach and psql clients

[dbist]

Describe the problem

CockroachDB supports PGSERVICEFILE based on the issue. Unfortunately, it only supports the basic capabilities and not the full scope of capabilities with psql.

To Reproduce

# CockroachDB Serverless
[serverless]
host=serverless.cockroachlabs.cloud
port=26257
user=artem
application_name=pgservicefile

psql service=serverless
psql (15.2 (Homebrew), server 13.0.0)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_128_GCM_SHA256, compression: off)
Type "help" for help.

artem=> show application_name;
 application_name 
------------------
 pgservicefile
(1 row)

with cockroach

cockroach sql --url "postgresql://artem@artem-serverless-3312.g8z.cockroachlabs.cloud?sslmode=verify-full&service=serverless"
#
# Welcome to the CockroachDB SQL shell.
# All statements must be terminated by a semicolon.
# To exit, type: \q.
#
# Client version: CockroachDB CCL v22.2.8 (aarch64-apple-darwin21.2, built 2023/04/17 13:51:03, go1.19.6)
# Server version: CockroachDB CCL v22.2.7 (x86_64-pc-linux-gnu, built 2023/03/28 19:47:29, go1.19.6)

warning: server version older than client! proceed with caution; some features may not be available.

# Cluster ID: 20735006-5a39-49c3-29b8-3d4c8befcbf8
#
# Enter \? for a brief introduction.
#
artem@artem-serverless-3312.g8z.cockroachlabs.cloud:26257/defaultdb> show application_name;
  application_name
--------------------
  $ cockroach sql
(1 row)

So the first thing you notice, it does not honor the application_name session variable. The other issue is you can't omit the user name from the connection string, even though it is in the file. You cannot omit the host either, the port however can be read from the file.

cockroach sql --url "postgresql://artem-serverless-3312.g8z.cockroachlabs.cloud?sslmode=verify-full&service=serverless"
#
# Welcome to the CockroachDB SQL shell.
# All statements must be terminated by a semicolon.
# To exit, type: \q.
#
Connecting to server "artem-serverless-3312.g8z.cockroachlabs.cloud:26257" as user "root".
Enter password: 

it prompts for password and it assumes the user is root.

Expected behavior

A UX similar to this should align with the way psql works

cockroach sql "service=serverless"
ERROR: unknown command "service=serverless" for "cockroach sql"
Failed running "sql"

Environment:

• CockroachDB version 22.2.8
• Server OS: Cockroach Cloud
• Client app cockroach sql, psql

Jira issue: CRDB-27158