Add localforage, basic cache service

package-lock.json

@@ -15545,6 +15545,12 @@
       "integrity": "sha512-MzbUSahkTW1u7JpKKjY7LCARd1fU5W2rLdxlM4kdkayuCwZImjkpluF9CM1aLewYJguPDqewLam18Y6AU69A8A==",
       "dev": true
     },
+    "immediate": {
+      "version": "3.0.6",
+      "resolved": "https://registry.npmjs.org/immediate/-/immediate-3.0.6.tgz",
+      "integrity": "sha1-nbHb0Pr43m++D13V5Wu2BigN5ps=",
+      "dev": true
+    },
     "import-fresh": {
       "version": "3.2.1",
       "resolved": "https://registry.npmjs.org/import-fresh/-/import-fresh-3.2.1.tgz",
@@ -16768,6 +16774,15 @@
         }
       }
     },
+    "lie": {
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/lie/-/lie-3.1.1.tgz",
+      "integrity": "sha1-mkNrLMd0bKWd56QfpGmz77dr2H4=",
+      "dev": true,
+      "requires": {
+        "immediate": "~3.0.5"
+      }
+    },
     "linkify-it": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/linkify-it/-/linkify-it-2.2.0.tgz",
@@ -16849,6 +16864,15 @@
       "integrity": "sha512-9M2KvGT6duzGMgkOcTkWb+PR/Q2Oe54df/tLgHGVmFpAmtqJ553xJh6N63iFYI2yjo2PeJXbS5skHi/QpJq4vA==",
       "dev": true
     },
+    "localforage": {
+      "version": "1.7.3",
+      "resolved": "https://registry.npmjs.org/localforage/-/localforage-1.7.3.tgz",
+      "integrity": "sha512-1TulyYfc4udS7ECSBT2vwJksWbkwwTX8BzeUIiq8Y07Riy7bDAAnxDaPU/tWyOVmQAcWJIEIFP9lPfBGqVoPgQ==",
+      "dev": true,
+      "requires": {
+        "lie": "3.1.1"
+      }
+    },
     "locate-character": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/locate-character/-/locate-character-2.0.5.tgz",