fix: mailservice should send non signed emails, if keystore isn't defied;

[smansoft]

---

Description

New version of json for configuring of smtp (i.e. all properties contain symbol '_'):

{
    "connectProtectionList":
        [
            "NONE",
            "START_TLS",
            "SSL_TLS"
        ],

    "trust_host": true,
    "connect_protection": "SslTls",
    "host": "smtp.gmail.com",
    "port": 465,
    "smtp_authentication_account_username": "sman2dev@gmail.com",
    "from_name": "Sergey Man",
    "from_email_address": "sman2dev@gmail.com",
    "requires_authentication": true,
    "smtp_authentication_account_password":"xxxxxxxxxxxxxxxx",
    "key_store":"/etc/certs/smtp-keys.p12",
    "key_store_password":"xxxxxxxxxxxxxxxx",
    "key_store_alias":"smtp_sig_ec256",
    "signing_algorithm":"SHA256withECDSA"
}

.
Configuring of smtp:

/opt/jans/jans-cli/config-cli.py --operation-id put-config-smtp --data ./smtp.json

.
Possible/supported case of configuring:

{
    "connectProtectionList":
        [
            "NONE",
            "START_TLS",
            "SSL_TLS"
        ],

    "trust_host": true,
    "connect_protection": "SslTls",
    "host": "smtp.gmail.com",
    "port": 465,
    "smtp_authentication_account_username": "sman2dev@gmail.com",
    "from_name": "Sergey Man",
    "from_email_address": "sman2dev@gmail.com",
    "requires_authentication": true,
    "smtp_authentication_account_password":"xxxxxxxxxxxxxxxx"
}

, i.e. this configuration json doesn't contain:

    "key_store": ...,
    "key_store_password": ...,
    "key_store_alias": ...,
    "signing_algorithm": ...

.
Sending of emails:

{
    "sign": true,
    "subject": "SMTP Configuration verification",
    "message": "Mail to test SMTP configuration"
}

or

{
    "sign": false,
    "subject": "SMTP Configuration verification",
    "message": "Mail to test SMTP configuration"
}

and:

/opt/jans/jans-cli/cli/config_cli.py --operation-id test-config-smtp --data ./smtp_test.json

.
If properties:

    "key_store": ...,
    "key_store_password": ...,
    "key_store_alias": ...,
    "signing_algorithm": ...

are not defined or some exception happened during reading of keystore (key, certificate),
MailService will try to send non-sigtned email, even, if "sign": true.

Issue: #4443.

[sonarcloud]

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[sonarcloud]

[Jans authentication server parent] Kudos, SonarCloud Quality Gate passed!   

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[sonarcloud]

[jans-config-api-parent] Kudos, SonarCloud Quality Gate passed!   

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0 Security Hotspots
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0.0% Coverage
0.0% Duplication