feat(webhooks): allow auth headers to be logged for debugging purposes

[bethesque]

With redaction

App logs

2022-10-07 10:35:51.905153 D [80210:worker-1] PactBroker::Webhooks::WebhookRequestLogger -- 
Webhook 7a5da39c-8e50-4cc9-ae16-dfa5be043e8c request 
headers={"accept"=>["*/*"], "user-agent"=>["Pact Broker v2.104.0"], "authorization"=>["**********"], 
"host"=>["postman-echo.com"], "content-length"=>["499"], "content-type"=>["application/x-www-form-urlencoded"]}

Logs returned via API

With redaction disabled

App logs

2022-10-07 10:51:28.802115 D [82363:worker-1] PactBroker::Webhooks::WebhookRequestLogger --
Webhook 7a5da39c-8e50-4cc9-ae16-dfa5be043e8c request
headers={"accept"=>["/"], "user-agent"=>["Pact Broker v2.104.0"], "authorization"=>["Basic dXNlcjpwYXNz"],
"host"=>["postman-echo.com"], "content-length"=>["499"], "content-type"=>["application/x-www-form-urlencoded"]}

Logs returned via API