chore: less warnings for docs generation (#9864)

* Hides the warnings about unresolved TypeScript symbols for the mixin base classes. Those warnings are not fixable and are polluting the Dgeni output.
* Adds missing `@deprecated` tags to entries that already have the  `@deletion-target` set.
* Updates to the latest version of dgeni-packages because https://github.com/angular/dgeni-packages/commit/3a4e5685589b99b85dfb88e8fd8dbf46aab24088 landed.

tools/dgeni/index.ts

@@ -1,4 +1,5 @@
 import {Package} from 'dgeni';
+import {patchLogService} from './patch-log-service';
 import {DocsPrivateFilter} from './processors/docs-private-filter';
 import {Categorizer} from './processors/categorizer';
 import {FilterDuplicateExports} from './processors/filter-duplicate-exports';
@@ -79,6 +80,9 @@ apiDocsPackage.config((readFilesProcessor: any, writeFilesProcessor: any) => {
   writeFilesProcessor.outputFolder = outputDir;
 });
 
+// Patches Dgeni's log service to not print warnings about unresolved mixin base symbols.
+apiDocsPackage.config((log: any) => patchLogService(log));
+
 // Configure the output path for written files (i.e., file names).
 apiDocsPackage.config((computePathsProcessor: any) => {
   computePathsProcessor.pathTemplates = [{

tools/dgeni/patch-log-service.ts

@@ -0,0 +1,24 @@
+
+/**
+ * Function that patches Dgeni's instantiated log service. The patch will hide warnings about
+ * unresolved TypeScript symbols for the mixin base classes.
+ *
+ * ```
+ * warn:    Unresolved TypeScript symbol(s): _MatToolbarMixinBase - doc "lib/toolbar/MatToolbar"
+ *    (class)  - from file "lib/toolbar/toolbar.ts" - starting at line 37, ending at line 98
+ * ```
+ *
+ * Those warnings are valid, but are not fixable because the base class is created dynamically
+ * through mixin functions and will be stored as a constant.
+ */
+export function patchLogService(log: any) {
+  const _warnFn = log.warn;
+
+  log.warn = function(message: string) {
+    if (message.includes('Unresolved TypeScript symbol') && message.includes('MixinBase')) {
+      return;
+    }
+
+    _warnFn.apply(this, [message]);
+  };
+}