Use haven for GDPR popup instead of cookieconsent

Haven is newer and more well maintained (and also it is actually
open source instead of open core with an upsell to a paid subscrip-
tion). Haven is configured to be 100% *opt-in* for Google Analytics,
which means it does not load or send a hit until the user agrees.

This is mostly a drop-in replacement, but translations need to make
sure the following strings are updated:

- cookieAccept
- cookieDecline

package-lock.json

@@ -4,6 +4,12 @@
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
+    "@chiiya/haven": {
+      "version": "0.6.0",
+      "resolved": "https://registry.npmjs.org/@chiiya/haven/-/haven-0.6.0.tgz",
+      "integrity": "sha512-t59swBfV/vxTu3TWedo+2NsniYsuCcLrPRSPs+7NbmMovCZntj+QDjGb+ZIzeYFGVzRfkN8XqRiuwt5/v0X+ng==",
+      "dev": true
+    },
     "@fortawesome/fontawesome-common-types": {
       "version": "0.2.28",
       "resolved": "https://registry.npmjs.org/@fortawesome/fontawesome-common-types/-/fontawesome-common-types-0.2.28.tgz",
@@ -1085,12 +1091,6 @@
       "integrity": "sha1-wguW2MYXdIqvHBYCF2DNJ/y4y3U=",
       "dev": true
     },
-    "cookieconsent": {
-      "version": "3.1.1",
-      "resolved": "https://registry.npmjs.org/cookieconsent/-/cookieconsent-3.1.1.tgz",
-      "integrity": "sha512-v8JWLJcI7Zs9NWrs8hiVldVtm3EBF70TJI231vxn6YToBGj0c9dvdnYwltydkAnrbBMOM/qX1xLFrnTfm5wTag==",
-      "dev": true
-    },
     "copy-concurrently": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/copy-concurrently/-/copy-concurrently-1.0.5.tgz",