SMTP credentials are stored in plain text - security concern

Overview:

mod-configuration is storing SMTP details, including SMTP username and password, in plaintext as config entries. Anyone with a valid okapi token can access these credentials and manipulate them. This is a security concern.

Steps to Reproduce:

1. Log into Morning Glory Bugfest

2. curl --location --request GET 'https://okapi-bugfest-mg.int.aws.folio.org/configurations/entries?limit=100&query=module==SMTP_SERVER' \--header 'x-okapi-tenant: fs09000000' \--header 'x-okapi-token: ${XOKAPITOKEN}'
   
   Response:   {
     "configs": [
       {
         "id": "bbc01fbf-2fa8-47c1-bae6-9b26cfbce3c9",
         "module": "SMTP_SERVER",
         "configName": "smtp",
         "code": "EMAIL_SMTP_HOST_DISABLED",
         "description": "",
         "default": true,
         "enabled": true,
         "value": "xxxxxxxxxxxxxxxxxx"
       },
       {
         "id": "37128a64-7da5-481e-958d-65d5ebe9cb02",
         "module": "SMTP_SERVER",
         "configName": "smtp",
         "code": "EMAIL_USERNAME",
         "description": "",
         "default": true,
         "enabled": true,
         "value": "xxxxxxxxxxxx"
       } ]

I have masked the credentials with x

Expected Results:

Credentials should not be stored in plaintext
Actual Results:

Credentials are stored in plaintext in the database
Additional Information:

Storing credentials in plain text in the database is not a good practice. These credentials are available to anyone who has mod-configuration enabled, which can be misused. I propose that mod-configuration stores the credentials in some kind of secret vault, for example, integrate with AWS Parameter store or secrets manager. There are also other options available, but they need to be investigated.

Note that this change will also affect mod-email. These credentials are fetched by mod-email for email verification - https://github.com/folio-org/mod-email/blob/9119fc3d40fe6dfc60b583f7fd29629f09473217/descriptors/ModuleDescriptor-template.json#L24

Interested parties: