fix(brave): robust ipfs.cat + content-type sniff

This applies cherry-picked patches from:
ipfs/js-ipfs#1989
ipfs/js-ipfs#1950
and solves stream issues on page refresh.

Content-type sniffing is now done over a meaningful amount of bytes
instead of arbitrary number.

Author: lidel

add-on/src/lib/on-installed.js

@@ -15,7 +15,7 @@ exports.showPendingLandingPages = async () => {
   const hint = await browser.storage.local.get('showLandingPage')
   switch (hint.showLandingPage) {
     case 'onInstallWelcome':
-      // TODO:restore await browser.storage.local.remove('showLandingPage')
+      await browser.storage.local.remove('showLandingPage')
       return browser.tabs.create({
         url: '/dist/landing-pages/welcome/index.html'
       })

package.json

@@ -121,9 +121,9 @@
     "filesize": "4.1.2",
     "http-dns": "3.0.1",
     "http-node": "1.2.0",
-    "ipfs": "https://github.com/lidel/js-ipfs/tarball/5a6327879a03aac95eb008f746455d7e22891a53/js-ipfs.tar.gz",
+    "ipfs": "https://github.com/lidel/js-ipfs/tarball/6197ced20dbcf5e4d699b67fbd6510d671a4dc52/js-ipfs.tar.gz",
     "ipfs-css": "0.12.0",
-    "ipfs-http-client": "30.1.0",
+    "ipfs-http-client": "30.1.2",
     "ipfs-http-response": "0.2.2",
     "ipfs-postmsg-proxy": "3.1.1",
     "ipfsx": "0.17.0",