feat(rdb): add config get command to generate database client snippets

[jremy42]

close #5501

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Relates OR Closes #0000

Release note for CHANGELOG:

[codecov-commenter]

❌ 3 Tests Failed:

Tests completed	Failed	Passed	Skipped
2428	3	2425	17

View the top 3 failed test(s) by shortest run time

github.com/scaleway/scaleway-cli/v2/cmd/scw::Test_AllUsage/rdb_config_usage

Stack Traces | 0.01s run time

=== RUN   Test_AllUsage/rdb_config_usage
=== PAUSE Test_AllUsage/rdb_config_usage
=== CONT  Test_AllUsage/rdb_config_usage
    main_test.go:37: 
        	Error Trace:	.../scaleway-cli/core/testing.go:779
        	            				.../scaleway-cli/core/testing.go:693
        	            				.../scaleway-cli/core/testing.go:523
        	Error:      	Received unexpected error:
        	            	open testdata/test-all-usage-rdb-config-usage.golden: no such file or directory
        	Test:       	Test_AllUsage/rdb_config_usage
        	Messages:   	expected to find golden file testdata/test-all-usage-rdb-config-usage.golden
--- FAIL: Test_AllUsage/rdb_config_usage (0.01s)

github.com/scaleway/scaleway-cli/v2/cmd/scw::Test_AllUsage/rdb_usage

Stack Traces | 0.01s run time

=== RUN   Test_AllUsage/rdb_usage
=== PAUSE Test_AllUsage/rdb_usage
=== CONT  Test_AllUsage/rdb_usage
    main_test.go:37: 
        	Error Trace:	.../scaleway-cli/core/testing.go:780
        	            				.../scaleway-cli/core/testing.go:693
        	            				.../scaleway-cli/core/testing.go:523
        	Error:      	Not equal: 
        	            	expected: "🎲🎲🎲 EXIT CODE: 0 🎲🎲🎲\n🟩🟩🟩 STDOUT️ 🟩🟩🟩️\nThis API allows you to manage your Managed Databases for PostgreSQL and MySQL.\n\nUSAGE:\n  scw rdb <command>\n\nAVAILABLE COMMANDS:\n  acl          Access Control List (ACL) management commands\n  backup       Backup management commands\n  database     Database management commands\n  endpoint     Endpoint management\n  engine       Database engines commands\n  instance     Instance management commands\n  log          Instance logs management commands\n  node-type    Node types management commands\n  privilege    User privileges management commands\n  read-replica Read replica management\n  setting      Setting management\n  snapshot     Block snapshot management\n  user         User management commands\n\nFLAGS:\n  -h, --help                help for rdb\n      --list-sub-commands   List all subcommands\n\nGLOBAL FLAGS:\n  -c, --config string    The path to the config file\n  -D, --debug            Enable debug mode\n  -o, --output string    Output format: json or human, see 'scw help output' for more info (default \"human\")\n  -p, --profile string   The config profile to use\n\nUse \"scw rdb [command] --help\" for more information about a command.\n"
        	            	actual  : "🎲🎲🎲 EXIT CODE: 0 🎲🎲🎲\n🟩🟩🟩 STDOUT️ 🟩🟩🟩️\nThis API allows you to manage your Managed Databases for PostgreSQL and MySQL.\n\nUSAGE:\n  scw rdb <command>\n\nAVAILABLE COMMANDS:\n  acl          Access Control List (ACL) management commands\n  backup       Backup management commands\n  config       Database client configuration snippets\n  database     Database management commands\n  endpoint     Endpoint management\n  engine       Database engines commands\n  instance     Instance management commands\n  log          Instance logs management commands\n  node-type    Node types management commands\n  privilege    User privileges management commands\n  read-replica Read replica management\n  setting      Setting management\n  snapshot     Block snapshot management\n  user         User management commands\n\nFLAGS:\n  -h, --help                help for rdb\n      --list-sub-commands   List all subcommands\n\nGLOBAL FLAGS:\n  -c, --config string    The path to the config file\n  -D, --debug            Enable debug mode\n  -o, --output string    Output format: json or human, see 'scw help output' for more info (default \"human\")\n  -p, --profile string   The config profile to use\n\nUse \"scw rdb [command] --help\" for more information about a command.\n"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -10,2 +10,3 @@
        	            	   backup       Backup management commands
        	            	+  config       Database client configuration snippets
        	            	   database     Database management commands
        	Test:       	Test_AllUsage/rdb_usage
--- FAIL: Test_AllUsage/rdb_usage (0.01s)

github.com/scaleway/scaleway-cli/v2/cmd/scw::Test_AllUsage

Stack Traces | 3.62s run time

=== RUN   Test_AllUsage
--- FAIL: Test_AllUsage (3.62s)

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[remyleone]

Could you remove that?

[remyleone]

Could you have gotemplates in a different folder?