Standardize SSL settings

[edmocosta]

Release notes

Standardized and added SSL settings

What does this PR do?

Standardized SSL settings by bumping the logstash-mixin-http_client version to >= 7.3.0, which:

• Adds standardized SSL settings and deprecates their non-standard counterparts. Deprecated settings will continue to work, and will provide pipeline maintainers with guidance toward using their standardized counterparts
• Adds new ssl_truststore_path, ssl_truststore_password, and ssl_truststore_type settings for configuring SSL-trust using a PKCS-12 or JKS trust store, deprecating their truststore, truststore_password, and truststore_type counterparts.
• Adds new ssl_certificate_authorities setting for configuring SSL-trust using a PEM-formatted list of certificate authorities, deprecating its cacert counterpart.
• Adds new ssl_keystore_path, ssl_keystore_password, and ssl_keystore_type settings for configuring SSL-identity using a PKCS-12 or JKS key store, deprecating their keystore, keystore_password, and keystore_type counterparts.
• Adds new ssl_certificate and ssl_key settings for configuring SSL-identity using a PEM-formatted certificate/key pair, deprecating their client_cert and client_key counterparts.
• Adds the ssl_cipher_suites option

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Closes elastic/logstash#14930

[roaksoax]

lgtm!