Make fomod selection flag matching case insensitive

Also add "action" to the list of values that should be interpreted as
True. Note that this doesn't make the actual flag names case
insensitive, just their values.

ammo/fomod_controller.py

@@ -161,14 +161,13 @@ def _get_pages(self) -> list[Page]:
                     # but fits into the "each step is a page" paradigm better.
                     if visible := step.find("visible"):
                         if dependencies := visible.find("dependencies"):
-                            dep_op = dependencies.get("operator")
-                            if dep_op:
-                                dep_op = dep_op.lower()
+                            dep_op = dependencies.get("operator", "").lower()
                             visibility_conditions["operator"] = dep_op
                             for xml_flag in dependencies:
-                                visibility_conditions[xml_flag.get("flag")] = (
-                                    xml_flag.get("value") in ["On", "1"]
-                                )
+                                if flag := xml_flag.get("flag"):
+                                    visibility_conditions[flag] = xml_flag.get(
+                                        "value", ""
+                                    ).lower() in ["on", "1", "active"]
 
                     page = Page(
                         name=group.get("name"),
@@ -192,10 +191,11 @@ def _get_pages(self) -> list[Page]:
                         if conditional_flags := plugin.find("conditionFlags"):
                             for flag in conditional_flags:
                                 # People use arbitrary flags here.
-                                # Most commonly "On" or "1".
-                                flags[flag.get("name")] = flag.text in [
-                                    "On",
+                                # Most commonly "On", "1" or "active".
+                                flags[flag.get("name")] = (flag.text or "").lower() in [
+                                    "on",
                                     "1",
+                                    "active",
                                 ]
                             conditional = True
 
@@ -318,15 +318,15 @@ def _get_nodes(self) -> list[ElementTree.Element]:
         )
         for pattern in patterns:
             dependencies = pattern.find("dependencies")
-            dep_op = dependencies.get("operator")
-            if dep_op:
-                dep_op = dep_op.lower()
+            dep_op = dependencies.get("operator", "").lower()
             expected_flags = {"operator": dep_op}
             for xml_flag in dependencies:
-                expected_flags[xml_flag.get("flag")] = xml_flag.get("value") in [
-                    "On",
-                    "1",
-                ]
+                if flag := xml_flag.get("flag"):
+                    expected_flags[flag] = xml_flag.get("value", "").lower() in [
+                        "on",
+                        "1",
+                        "active",
+                    ]
 
             # xml_files is a list of folders. The folder objects contain the paths.
             xml_files = pattern.find("files")