feat: Add ent-based sqlite3 storage

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

storage/ent/schema/connector.go

@@ -0,0 +1,46 @@
+package schema
+
+import (
+	"github.com/facebook/ent"
+	"github.com/facebook/ent/schema/field"
+)
+
+/* Original SQL table:
+create table connector
+(
+    id               text not null  primary key,
+    type             text not null,
+    name             text not null,
+    resource_version text not null,
+    config           blob
+);
+*/
+
+// Connector holds the schema definition for the Client entity.
+type Connector struct {
+	ent.Schema
+}
+
+// Fields of the Connector.
+func (Connector) Fields() []ent.Field {
+	return []ent.Field{
+		field.Text("id").
+			SchemaType(textSchema).
+			NotEmpty().
+			Unique(),
+		field.Text("type").
+			SchemaType(textSchema).
+			NotEmpty(),
+		field.Text("name").
+			SchemaType(textSchema).
+			NotEmpty(),
+		field.Text("resource_version").
+			SchemaType(textSchema),
+		field.Bytes("config"),
+	}
+}
+
+// Edges of the Connector.
+func (Connector) Edges() []ent.Edge {
+	return []ent.Edge{}
+}