fix(@schematics/angular): add browserslist configuration in library projects

Previously, browserslist configuration was not added in library projects. This in some cases caused a large number of CSS prefixes to be included in components stylesheets

Author: alan-agius4

packages/schematics/angular/library/files/.browserslistrc.template

@@ -0,0 +1,16 @@
+# This file is used by the build system to adjust CSS and JS output to support the specified browsers below.
+# For additional information regarding the format and rule options, please see:
+# https://github.com/browserslist/browserslist#queries
+
+# For the full list of supported browsers by the Angular framework, please see:
+# https://angular.io/guide/browser-support
+
+# You can see what browsers were selected by your queries by running:
+#   npx browserslist
+
+last 1 Chrome version
+last 1 Firefox version
+last 2 Edge major versions
+last 2 Safari major versions
+last 2 iOS major versions
+Firefox ESR