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/config/database.go

@@ -0,0 +1,19 @@
+package config
+
+import "time"
+
+type SupportedDatabase string
+
+const (
+	DatabaseMySQL    SupportedDatabase = "mysql"
+	DatabaseMsSQL    SupportedDatabase = "mssql"
+	DatabasePostgres SupportedDatabase = "postgres"
+	DatabaseSQLite   SupportedDatabase = "sqlite"
+)
+
+type DatabaseConfig struct {
+	Debug              bool              `yaml:"debug"`
+	SlowQueryThreshold time.Duration     `yaml:"slow_query_threshold"` // 0 means no logging of slow queries
+	Type               SupportedDatabase `yaml:"type"`
+	DSN                string            `yaml:"dsn"` // On SQLite: the database file-path, otherwise the dsn (see: https://gorm.io/docs/connecting_to_the_database.html)
+}