feat: Add ent-based sqlite3 storage

Signed-off-by: m.nabokikh <maksim.nabokikh@flant.com>

storage/ent/schema/password.go

@@ -0,0 +1,44 @@
+package schema
+
+import (
+	"github.com/facebook/ent"
+	"github.com/facebook/ent/schema/field"
+)
+
+/* Original SQL table:
+create table password
+(
+    email    text not null  primary key,
+    hash     blob not null,
+    username text not null,
+    user_id  text not null
+);
+*/
+
+// Password holds the schema definition for the Password entity.
+type Password struct {
+	ent.Schema
+}
+
+// Fields of the Password.
+func (Password) Fields() []ent.Field {
+	return []ent.Field{
+		field.Text("email").
+			SchemaType(textSchema).
+			StorageKey("email"). // use email as ID field to make querying easier
+			NotEmpty().
+			Unique(),
+		field.Bytes("hash"),
+		field.Text("username").
+			SchemaType(textSchema).
+			NotEmpty(),
+		field.Text("user_id").
+			SchemaType(textSchema).
+			NotEmpty(),
+	}
+}
+
+// Edges of the Password.
+func (Password) Edges() []ent.Edge {
+	return []ent.Edge{}
+}