Please add TLS/SSL support to syslog input plugin.

**Is your feature request related to a problem? Please describe.**
I'm only able to send syslog messages to fluent-bit across a network using plain text UDP or TCP.

**Describe the solution you'd like**
Please add TLS support to the syslog input plugin.

**Describe alternatives you've considered**
I'm currently running a sidecar container with nginx to terminate SSL and write to a syslog socket file (into fluent-bit). I'd like to not have to run nginx, and instead pass an SSL cert/CA/key into fluent-bit directly.

**Additional context**
Amazon requires all service-to-service communications to be encrypted in flight. Per company policy, this missing feature means Amazon employees have a difficult time utilizing the syslog input plugin [without an nginx sidecar].