More precise control over logs verbosity at startup

[w23]

Currently -vkverboselogs enables verbose logs for all ref_vk modules. Having too many logs is often inconvenient.

We'd use cvars for per-module log control, but cvars are loaded too late.

What we can do is use environment variables to list modules for which verbose logs should be enabled. E.g.: XASH_REF_VK_LOGS=mat,tex,patch

[w23]

Just use vk_debug_log "mat,tex" in e.g. valve/autoexec.cfg you dummy. No need to mess with env vars.

[w23]

autoexec.cfg is still too late. ref_vk initialization happens before it is read.

What can be done:

• environment vars
• cmdline args, e.g. -vkdbgtex, -vkdbgmat, etc.. Xash doesn't expose the list of variables, we can only check whether a given string is in args.