When specifying --root-cas for tls or https, only parse the file once

[codyprime]

When the --root-cas= option is used for tls or https scans, the function GetTLSConfigForTarget is called to load the Root CAs into the TLS Config options. This happens for each scan, so the end result is heap and goroutine usage increases continually, eventually consuming all machine resources.

This option should be parsed only once, and loaded into a shared object for all scans.