feat: use go1.16 and resources embedding (#235)

* feat: use go1.16 embedding for resources

We want to embed everything that can be easily embedded. We should, at a
minimum, replace the downloading of resources and bindata.

Ref: https://github.com/ooni/probe/issues/1367.

* fix: get rid of bindata and use go embed instead

* fix: start unbreaking some automatic tests

* fix: fetch resources as part of the mobile build

* fix: convert more stuff to go1.16

I still expect many breakages, but we'll fix them.

* fix: make the windows CI green

* fix: get resources before running QA

* fix: go1.16 uses modules by default

* hopefully fix all other outstanding issues

* fix(QA/telegram.py): add another DC IP address

* Apply suggestions from code review

data/default-config.json

@@ -1,13 +0,0 @@
-{
-  "_version": 1,
-  "_informed_consent": false,
-  "sharing": {
-    "upload_results": true
-  },
-  "nettests": {
-    "websites_url_limit": 0
-  },
-  "advanced": {
-    "send_crash_reports": true
-  }
-}