Binary files are not encrypted when encrypted_suffix is specified

Hello,

I'm using 3.7.1 on Ubuntu 20.04.3 LTS. I noticed that binary files are not encrypted by sops, when encrypted_suffix is provided in .sops.yaml. See below files for an example.

# secret.txt
this is a secret value

# .sops.yaml
---
creation_rules:
  - path_regex: 'secret\.txt'
    encrypted_suffix: _encrypted
    key_groups:
      - pgp:
          - ... # valid fingerprint

Next enter the following command: sops -e secret.txt > secret.txt.sopsenc.json. As a result of this command I get the following file:

{
	"data": "this is a secret value",
	"sops": {
		"...": null,
		"mac": "ENC[...]",
		"pgp": [
			{
				"created_at": "2022-01-10T14:25:14Z",
				"enc": "...",
				"fp": "..."
			}
		],
		"encrypted_suffix": "_encrypted",
		"version": "3.7.1"
	}
}

But I expect such a file:

{
	"data_encrypted": "ENC[...]",
	"sops": {
		"...": null,
		"mac": "ENC[...]",
		"pgp": [
			{
				"created_at": "2022-01-10T14:25:14Z",
				"enc": "...",
				"fp": "..."
			}
		],
		"encrypted_suffix": "_encrypted",
		"version": "3.7.1"
	}
}

I see two solutions for this case:

1. automatic append value of encrypted_suffix key to data key name, but in this case encrypted_regex still will not work,
2. add new configuration key, like data_key_name, that will have value data_encrypted in my case, so will work regardless of encrypted_* setting.

Thank you in advance for considering my request

Regards
Piotr Minkina

Reproduce the report with the shown .sops.yaml and sops -e secret.txt command, comparing the produced JSON with the expected data_encrypted output. Trace how encrypted_suffix is handled for the binary/JSON output path, then add coverage for the reported case and verify that the resulting data key is encrypted without regressing other encrypted_* settings.