frontend: Support enhanced broadcasting on Linux

Enhanced broadcasting requires system information to be gathered
on the client and submitted to the GetClientConfiguration request
in order to obtain a valid response from the server. This commit
adds support for gathering the required information on Linux-based
systems.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f