Incoming permissions logs - handle data in invalid format

[MarcinFalkowski]

Currently we produce incoming permissions logs as a JSON, which is prepared in a non-reliable way. If particular characters (for example ") will be present in x-service-name header, the result JSON will be invalid.

To consider:

1. Fetch serviceName from client certificate SAN URI, instead of a header.
2. Change log format to something simpler than JSON, for example "every field in a new line"
3. Sanitize JSON strings

More information: #152 (comment)