I18n: Disambiguate "Space"

- "Space" can be the spacebar key. This uses the UIEvents context
  already. One instance is the event type enum item, where "Spacebar"
  is the label and "Space" is the description. Since there is no way
  to use contexts for descriptions since they are supposed to be more
  verbose, the label was renamed to "Space Bar" (acceptable according
  to Wikipedia), and the description to "Spacebar".
- In the context of the Grease Pencil, "Space" is a method of spacing
  brush strokes.

Issue reported by Hoang Duy Tran.

source/blender/editors/interface/interface_icons_event.cc

@@ -286,7 +286,12 @@ void icon_draw_rect_input(const float x,
     icon_draw_rect_input_text(&rect, BLI_STR_UTF8_DOWNWARDS_ARROW, aspect, alpha, inverted);
   }
   else if (icon_id == ICON_EVENT_SPACEKEY) {
-    icon_draw_rect_input_text(&rect, IFACE_("Space"), aspect, alpha, inverted, ICON_KEY_EMPTY3);
+    icon_draw_rect_input_text(&rect,
+                              CTX_IFACE_(BLT_I18NCONTEXT_UI_EVENTS, "Space"),
+                              aspect,
+                              alpha,
+                              inverted,
+                              ICON_KEY_EMPTY3);
   }
   else if (icon_id == ICON_EVENT_MOUSE_4) {
     icon_draw_rect_input_text(

source/blender/makesrna/intern/rna_brush.cc

@@ -2625,6 +2625,7 @@ static void rna_def_brush(BlenderRNA *brna)
   RNA_def_property_enum_items(prop, sculpt_stroke_method_items);
   RNA_def_property_enum_funcs(prop, nullptr, nullptr, "rna_Brush_stroke_itemf");
   RNA_def_property_ui_text(prop, "Stroke Method", "");
+  RNA_def_property_translation_context(prop, BLT_I18NCONTEXT_ID_GPENCIL);
   RNA_def_property_update(prop, 0, "rna_Brush_stroke_update");
 
   prop = RNA_def_property(srna, "sculpt_plane", PROP_ENUM, PROP_NONE);
@@ -3585,6 +3586,7 @@ static void rna_def_brush(BlenderRNA *brna)
   RNA_def_property_boolean_sdna(prop, nullptr, "flag", BRUSH_SPACE);
   RNA_def_property_ui_text(
       prop, "Space", "Limit brush application to the distance specified by spacing");
+  RNA_def_property_translation_context(prop, BLT_I18NCONTEXT_ID_GPENCIL);
   RNA_def_property_update(prop, 0, "rna_Brush_update");
 
   prop = RNA_def_property(srna, "use_line", PROP_BOOLEAN, PROP_NONE);

source/blender/makesrna/intern/rna_wm.cc

@@ -282,7 +282,7 @@ const EnumPropertyItem rna_enum_event_type_items[] = {
     {EVT_ESCKEY, "ESC", 0, "Esc", ""},
     {EVT_TABKEY, "TAB", 0, "Tab", ""},
     {EVT_RETKEY, "RET", 0, "Return", "Enter"},
-    {EVT_SPACEKEY, "SPACE", 0, "Spacebar", "Space"},
+    {EVT_SPACEKEY, "SPACE", 0, "Space Bar", "Spacebar"},
     {EVT_LINEFEEDKEY, "LINE_FEED", 0, "Line Feed", ""},
     {EVT_BACKSPACEKEY, "BACK_SPACE", 0, "Backspace", "BkSpace"},
     {EVT_DELKEY, "DEL", 0, "Delete", "Del"},

source/blender/windowmanager/intern/wm_keymap.cc

@@ -1161,7 +1161,8 @@ const char *WM_key_event_string(const short type, const bool compact)
       case EVT_RETKEY:
         return key_event_glyph_or_text(font_id, IFACE_("Enter"), BLI_STR_UTF8_RETURN_SYMBOL);
       case EVT_SPACEKEY:
-        return key_event_glyph_or_text(font_id, IFACE_("Space"), BLI_STR_UTF8_OPEN_BOX);
+        return key_event_glyph_or_text(
+            font_id, CTX_IFACE_(BLT_I18NCONTEXT_UI_EVENTS, "Space"), BLI_STR_UTF8_OPEN_BOX);
       case EVT_LEFTARROWKEY:
         return key_event_glyph_or_text(font_id, IFACE_("Left"), BLI_STR_UTF8_LEFTWARDS_ARROW);
       case EVT_UPARROWKEY: