Return comments for hosts over RPC

[sjanusz-r7]

Closes #21247

Tested in Pro. No impact, everything works. We don't display host comments anywhere in Pro's UI.

Before

No comment

>> rpc.call("db.hosts", {})
=> 
{"hosts"=>
  [{"created_at"=>1776160363,
    "address"=>"127.0.0.1",
    "mac"=>"",
    "name"=>"caea2eea7ecb",
    "state"=>"alive",
    "os_name"=>"Debian 9.6 (Linux 6.12.76-linuxkit)",
    "os_flavor"=>"",
    "os_sp"=>"",
    "os_lang"=>"",
    "updated_at"=>1776160491,
    "purpose"=>"server",
    "info"=>""}]}

After

With a comment

>> rpc.call("db.hosts", {})
=> 
{"hosts"=>
  [{"created_at"=>1776160363,
    "address"=>"127.0.0.1",
    "mac"=>"",
    "name"=>"caea2eea7ecb",
    "state"=>"alive",
    "os_name"=>"Debian 9.6 (Linux 6.12.76-linuxkit)",
    "os_flavor"=>"",
    "os_sp"=>"",
    "os_lang"=>"",
    "updated_at"=>1776160491,
    "purpose"=>"server",
    "info"=>"",
    "comments"=>"hello world, this is a comment"}]}

Verification

List the steps needed to make sure this thing works

• Have a host in the database (you can run a module, or hosts -a x.x.x.x
• Add comment to host using the IP hosts -m "this is an example comment" x.x.x.x
• Boot RPC server using load msgrpc
• Connect to RPC with msfrpc
• run `rpc.call("db.hosts", {})
• Confirm comment is visible
• Verify that a host without a comment in msfconsole does not crash. Instead it returns "comments"=>""

[sjanusz-r7]

Other lines here use .to_s as well, resulting in an empty string instead of a nil value. This follows a pattern, but unsure if the .to_s should be dropped (nil vs. empty string).

[Copilot]

Pull request overview

This PR updates the db.hosts RPC response so host records include their comments field, aligning RPC output with what hosts shows in msfconsole and addressing issue #21247.

Changes:

• Add comments to each host entry returned by rpc_hosts in the RPC DB API.

[adfoster-r7]

Release Notes

Updates the db.hosts RPC call to now additionally include the comments associated with the host