Rename BaseConf.New to BaseConf.Get

Since BaseConf.New could return a cached BaseConf, rather than always
constructing a new struct, I've renamed it to Get to more accurately
reflect its use. A new New() method is called by Get and always
initializes a new struct.

Signed-off-by: Jonathon Anderson <janderson@ciq.co>

internal/app/wwctl/container/list/main_test.go

@@ -55,7 +55,7 @@ nodes:
 WW_INTERNAL: 0
     `
 
-	conf := warewulfconf.New()
+	conf := warewulfconf.Get()
 	err := conf.Read([]byte(conf_yml))
 	assert.NoError(t, err)
 	warewulfd.SetNoDaemon()