feat: read tor cookies from a file

[therustmonk]

Description

The PR adds a capability to read a tor cookie from a file.
To set a cookie value in the config of the tari_base_node we could use three ways:

tor.control_auth = "cookie=HEX"
tor.control_auth = "cookie=@" # read `/run/tor/control.authcookie` default cookie file
tor.control_auth = "cookie=@/custom/path/to/cookie/file"

Motivation and Context

Fixes #2808

How Has This Been Tested?

CI and manually (Fedora 35, stardard tor service + added ControlPort to the config)

[sdbondi]

Looks good! utAck