Create a new hook that happens before most GUT scripts are loaded

[bitwes]

Versions

Godot 4 and probably 3

The Feature

In conjuring up #605 I had the thought that a hook script, would allow users to set gdscript warning values themselves. There is probably other uses for this hook as well. This wouldn't be as nice or as visible as as making all those cool widgets for the editor, but it would be a good first step, plus whatever else people could use it for.

The hook script would be called from GutRunner in _ready. It could probably be called first, unless there are some GUT features that would be useful to have access to. It must be called before any calls to GutUtils.get_instance(), since this will load all GUT scripts on instantiation. It also must be called before any test scripts are loaded, but that happens well after the first all to GutUtils.get_instance(). It should support abort and set_exit_code. If #605 is implemented then this should probably be called after project settings are set.