Update validator status and filter status footer displays

(re: #449)

Both of these are class components now that can rerender as needed.

The validator status widget didn't seem to be updating its count correctly,
I think this is now fixed.

The filter status had been commented out since the v2 rewrite.  This commit
adds bunch of changes in the FilterSystem to improve a lot of what it does.
This was commented out because we were not actually gathering any statistics
because so much about how the scene is drawn now has changed from the v1 days.

One big issue with the old `FilterSystem.getMatches` code was that there was a
requirement that parent relations must get matched before child ways.
Now, `getMatches` will recurse up if it detects that a parent hasn't done its
matching before the child. These functions all have some agressive caching
so it performs well.

It would not surprise me if this was causing some issues with landuse or boundary
multipolygons not filtering their child ways correctly.

css/80_app.css

@@ -4573,10 +4573,10 @@ li.issue-fix-item button:not(.actionable) .fix-icon {
 }
 
 .issues-info a.chip.resolved-count {
-  background: #15911E;
+  background: #15911e;
 }
 .issues-info a.chip.warnings-count {
-  background: #DF8500;
+  background: #df8500;
 }
 .ideditor[dir='ltr'] .issues-info a.chip:not(:last-child) {
   margin-right: 5px;

data/core.yaml

@@ -359,7 +359,7 @@ en:
           multiple: Flip these features across their short axis.
       key:
         long: T
-        short: Y
+        short: "Y"
       annotation:
         long:
           feature:
@@ -708,9 +708,6 @@ en:
     multiple_values: Multiple Values
     multiple_types: Multiple Types
     unshared_value_tooltip: not shared by all features
-    hidden_preset:
-      manual: "{features} are hidden. Enable them in the Map Data pane."
-      zoom: "{features} are hidden. Zoom in to enable them."
     back_tooltip: Change feature type
     type: Type
     details: Details
@@ -952,6 +949,10 @@ en:
     full:
       description: Full Fill
       tooltip: "Areas are drawn fully filled."
+  filters:
+    hidden_preset:
+      manual: "{features} are filtered. Enable them in the Map Data pane."
+    active: "Some features are filtered:"
   settings:
     custom_background:
       tooltip: Edit custom background

data/l10n/core.en.json

@@ -911,10 +911,6 @@
       "multiple_values": "Multiple Values",
       "multiple_types": "Multiple Types",
       "unshared_value_tooltip": "not shared by all features",
-      "hidden_preset": {
-        "manual": "{features} are hidden. Enable them in the Map Data pane.",
-        "zoom": "{features} are hidden. Zoom in to enable them."
-      },
       "back_tooltip": "Change feature type",
       "type": "Type",
       "details": "Details",
@@ -1216,6 +1212,12 @@
         "tooltip": "Areas are drawn fully filled."
       }
     },
+    "filters": {
+      "hidden_preset": {
+        "manual": "{features} are filtered. Enable them in the Map Data pane."
+      },
+      "active": "Some features are filtered:"
+    },
     "settings": {
       "custom_background": {
         "tooltip": "Edit custom background",