refactor(platform-browser): further reduce runtime code size of shared style host

The `SharedStylesHost` class has been refactored to further reduce
the runtime code size. SSR generated component styles are now added directly
into the usage records to avoid the need for additional data structures and
lookups when adding a component style. The code reduction in a prerelease
newly generated Angular CLI application for production is ~190 bytes.

Before:
```
Initial chunk files   | Names         |  Raw size | Estimated transfer size
main-3X2VHGTM.js      | main          | 208.26 kB |                56.30 kB
polyfills-FFHMD2TL.js | polyfills     |  34.52 kB |                11.28 kB
styles-5INURTSO.css   | styles        |   0 bytes |                 0 bytes

                      | Initial total | 242.78 kB |                67.58 kB
```

After:
```
Initial chunk files   | Names         |  Raw size | Estimated transfer size
main-MGOZ6Q4F.js      | main          | 208.07 kB |                56.26 kB
polyfills-FFHMD2TL.js | polyfills     |  34.52 kB |                11.28 kB
styles-5INURTSO.css   | styles        |   0 bytes |                 0 bytes

                      | Initial total | 242.59 kB |                67.54 kB
```

Author: clydin

packages/core/test/bundling/animations-standalone/bundle.golden_symbols.json

@@ -827,6 +827,9 @@
   {
     "name": "createNotification"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1356,10 +1359,10 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeClass"
   },
   {
-    "name": "removeClass"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/animations/bundle.golden_symbols.json

@@ -890,6 +890,9 @@
   {
     "name": "createPlatformFactory"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1431,10 +1434,10 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeClass"
   },
   {
-    "name": "removeClass"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/cyclic_import/bundle.golden_symbols.json

@@ -683,6 +683,9 @@
   {
     "name": "createPlatformFactory"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1158,7 +1161,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/defer/bundle.golden_symbols.json

@@ -761,6 +761,9 @@
   {
     "name": "createNotification"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -2406,7 +2409,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json

@@ -980,6 +980,9 @@
   {
     "name": "createPlatformFactory"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1725,7 +1728,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json

@@ -944,6 +944,9 @@
   {
     "name": "createPlatformFactory"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1692,7 +1695,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/hydration/bundle.golden_symbols.json

@@ -746,6 +746,9 @@
   {
     "name": "createOperatorSubscriber"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1268,15 +1271,15 @@
   {
     "name": "remove"
   },
-  {
-    "name": "removeAll"
-  },
   {
     "name": "removeDehydratedView"
   },
   {
     "name": "removeDehydratedViews"
   },
+  {
+    "name": "removeElements"
+  },
   {
     "name": "removeFromArray"
   },

packages/core/test/bundling/router/bundle.golden_symbols.json

@@ -1121,6 +1121,9 @@
   {
     "name": "createSegmentGroupFromRoute"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1965,7 +1968,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/standalone_bootstrap/bundle.golden_symbols.json

@@ -614,6 +614,9 @@
   {
     "name": "createNotification"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1020,7 +1023,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"

packages/core/test/bundling/todo/bundle.golden_symbols.json

@@ -800,6 +800,9 @@
   {
     "name": "createPlatformFactory"
   },
+  {
+    "name": "createStyleElement"
+  },
   {
     "name": "createTView"
   },
@@ -1374,7 +1377,7 @@
     "name": "remove"
   },
   {
-    "name": "removeAll"
+    "name": "removeElements"
   },
   {
     "name": "removeFromArray"