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

internal/cmd/jafar/README.md

@@ -8,7 +8,7 @@ any system but it really on works on Linux.
 
 ## Building
 
-We use Go >= 1.14. Jafar also needs the C library headers,
+We use Go >= 1.16. Jafar also needs the C library headers,
 iptables installed, and root permissions.
 
 With Linux Alpine edge, you can compile Jafar with: