V2 alpha - initial version (#172)

Initial alpha codebase for version 2 of WireGuard Portal.
This version is considered unstable and incomplete (for example, no public REST API)! 
Use with care!


Fixes/Implements the following issues:
 - OAuth support #154, #1 
 - New Web UI with internationalisation support #98, #107, #89, #62
 - Postgres Support #49 
 - Improved Email handling #47, #119 
 - DNS Search Domain support #46 
 - Bugfixes #94, #48 

---------

Co-authored-by: Fabian Wechselberger <wechselbergerf@hotmail.com>

internal/app/api/v0/handlers/encoding.go

@@ -0,0 +1,15 @@
+package handlers
+
+import (
+	"encoding/base64"
+	"strings"
+)
+
+func Base64UrlDecode(in string) string {
+	in = strings.ReplaceAll(in, "-", "=")
+	in = strings.ReplaceAll(in, "_", "/")
+	in = strings.ReplaceAll(in, ".", "+")
+
+	output, _ := base64.StdEncoding.DecodeString(in)
+	return string(output)
+}