Convert db backend to use Gorm, with basis for support

for Mysql and Postgres in addition to existing Sqlite

backend/internal/entity/capability.go

@@ -0,0 +1,11 @@
+package entity
+
+// Capability is the db model
+type Capability struct {
+	Name string `json:"name" gorm:"column:name;primaryKey" filter:"name,string"`
+}
+
+// TableName overrides the table name used by gorm
+func (Capability) TableName() string {
+	return "capability"
+}