Fix T97429: Translateable Unit Names Missing in the File.

Added some regex magic in i18n py module to also extract UI names from
all of our units definitions.

Those enum values are fully dynamically generated, so they cannot be
extracted from RNA introspection.

release/scripts/modules/bl_i18n_utils/settings.py

@@ -253,6 +253,14 @@ PYGETTEXT_KEYWORDS = (() +
     tuple(("{}\\((?:[^\"',]+,)\\s*" + _msg_re + r"\s*(?:\)|,)").format(it)
           for it in ("BKE_modifier_set_error",)) +
 
+    # bUnitDef unit names.
+    # NOTE: regex is a bit more complex than it would need too. Since the actual
+    # identifier (`B_UNIT_DEF_`) is at the end, if it's simpler/too general it
+    # becomes extremely slow to process some (unrelated) source files. 
+    ((r"\{(?:(?:\s*\"[^\"',]+\"\s*,)|(?:\s*NULL\s*,)){4}\s*" +
+      _msg_re + r"\s*,(?:(?:\s*\"[^\"',]+\"\s*,)|(?:\s*NULL\s*,))(?:[^,]+,){2}"
+      + "\s*B_UNIT_DEF_[_A-Z]+\s*\}"),) +
+
     tuple((r"{}\(\s*" + _msg_re + r"\s*,\s*(?:" +
            r"\s*,\s*)?(?:".join(_ctxt_re_gen(i) for i in range(PYGETTEXT_MAX_MULTI_CTXT)) + r")?\s*\)").format(it)
           for it in ("BLT_I18N_MSGID_MULTI_CTXT",))

source/blender/makesrna/intern/rna_scene.c

@@ -2630,7 +2630,7 @@ static const EnumPropertyItem *rna_UnitSettings_itemf_wrapper(const int system,
 
   EnumPropertyItem adaptive = {0};
   adaptive.identifier = "ADAPTIVE";
-  adaptive.name = "Adaptive";
+  adaptive.name = N_("Adaptive");
   adaptive.value = USER_UNIT_ADAPTIVE;
   RNA_enum_item_add(&items, &totitem, &adaptive);