[UI] IDE/SSH access via SSH Proxy

[un-def]

Currently, the only option to connect to the job offered by UI is the dstack attach flow:

When SSH proxy is enabled, it's possible to connect to the job directly, without dstack installed, but this flow is not exposed via UI.

All required information is available in the /api/project/:project/runs/get API method response, namely the jobs[].job_connection_info fields – ide_name, proxied_ide_url, proxied_ssh_command:

{
	"job_connection_info": {
		"ide_name": "VS Code",
		"attached_ide_url": "vscode://vscode-remote/ssh-remote+dev-environment/dstack/run",
		"proxied_ide_url": "vscode://vscode-remote/ssh-remote+bc7f75a4b92d4d34a0635b7e72a5b271@localhost:30022/dstack/run",
		"attached_ssh_command": [
			"ssh",
			"dev-environment"
		],
		"proxied_ssh_command": [
			"ssh",
			"bc7f75a4b92d4d34a0635b7e72a5b271@localhost",
			"-p",
			"30022"
		],
		"sshproxy_hostname": "localhost",
		"sshproxy_port": 30022,
		"sshproxy_upstream_id": "bc7f75a4b92d4d34a0635b7e72a5b271"
	}
}