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

cmd/ooniprobe/internal/ooni/default-config.json

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

cmd/ooniprobe/internal/ooni/ooni.go

@@ -1,6 +1,7 @@
 package ooni
 
 import (
+	_ "embed" // because we embed a file
 	"io/ioutil"
 	"os"
 	"os/signal"
@@ -8,7 +9,6 @@ import (
 	"syscall"
 
 	"github.com/apex/log"
-	"github.com/ooni/probe-cli/v3/cmd/ooniprobe/internal/bindata"
 	"github.com/ooni/probe-cli/v3/cmd/ooniprobe/internal/config"
 	"github.com/ooni/probe-cli/v3/cmd/ooniprobe/internal/database"
 	"github.com/ooni/probe-cli/v3/cmd/ooniprobe/internal/enginex"
@@ -239,6 +239,9 @@ func MaybeInitializeHome(home string) error {
 	return nil
 }
 
+//go:embed default-config.json
+var defaultConfig []byte
+
 // InitDefaultConfig reads the config from common locations or creates it if
 // missing.
 func InitDefaultConfig(home string) (*config.Config, error) {
@@ -252,12 +255,7 @@ func InitDefaultConfig(home string) (*config.Config, error) {
 	if err != nil {
 		if os.IsNotExist(err) {
 			log.Debugf("writing default config to %s", configPath)
-			var data []byte
-			data, err = bindata.Asset("data/default-config.json")
-			if err != nil {
-				return nil, err
-			}
-			if err = ioutil.WriteFile(configPath, data, 0644); err != nil {
+			if err = ioutil.WriteFile(configPath, defaultConfig, 0644); err != nil {
 				return nil, err
 			}
 			// If the user did the informed consent procedure in