feat(chatwoot): import history messages to chatwoot on whatsapp connection

Messages are imported direct to chatwoot database. Media and group messages are ignored.

New env.yml variables:
CHATWOOT_IMPORT_DATABASE_CONNECTION_URI: URI to connect direct on chatwoot database.
CHATWOOT_IMPORT_PLACEHOLDER_MEDIA_MESSAGE: Indicates to use a text placeholder on media messages.

New instance setting:
sync_full_history: Indicates to request a full history sync to baileys.

New chatwoot options:
import_contacts: Indicates to import contacts.
import_messages: Indicates to import messages.
days_limit_import_messages: Number of days to limit history messages to import.

src/libs/postgres.client.ts

@@ -0,0 +1,49 @@
+import postgresql from 'pg';
+
+import { Chatwoot, configService } from '../config/env.config';
+import { Logger } from '../config/logger.config';
+
+const { Pool } = postgresql;
+
+class Postgres {
+  private logger = new Logger(Postgres.name);
+  private pool;
+  private connected = false;
+
+  getConnection(connectionString: string) {
+    if (this.connected) {
+      return this.pool;
+    } else {
+      this.pool = new Pool({
+        connectionString,
+        ssl: {
+          rejectUnauthorized: false,
+        },
+      });
+
+      this.pool.on('error', () => {
+        this.logger.error('postgres disconnected');
+        this.connected = false;
+      });
+
+      try {
+        this.logger.verbose('connecting new postgres');
+        this.connected = true;
+      } catch (e) {
+        this.connected = false;
+        this.logger.error('postgres connect exception caught: ' + e);
+        return null;
+      }
+
+      return this.pool;
+    }
+  }
+
+  getChatwootConnection() {
+    const uri = configService.get<Chatwoot>('CHATWOOT').IMPORT.DATABASE.CONNECTION.URI;
+
+    return this.getConnection(uri);
+  }
+}
+
+export const postgresClient = new Postgres();