Arduino Text Scrolling on 16x02 I2c on NodeMcu (esp8266-12)

The main part of the code, based on your original sketch, should look like this:

 // Read all the lines of the reply from server and print them to Serial
  while (client.available()) {
    String line = client.readStringUntil('\r');

    int start_loc = find_text("<b>", line, 0);
    int end_loc = find_text("</b>", line, 0);   
    if (start_loc > 0 && end_loc > 0)
    {
      lcd.clear();
      Serial.println("data:  ");
      lcd.print("data: ");
      lcd.setCursor(1, 1);
      // dump line read to lcd. scroll if necessary . . .
      if ( line.length() <= 16 ) {
        Serial.println( line ) ;
        lcd.print( line ) ;
      }
      else {
        for ( int i = 0 ; i <= line.length() - 16 ; i++ ) {
          Serial.println( line.substring( i, i + 16 ) ) ;
          lcd.print( line.substring( i, i + 16 ) ) ;
          delay( 500 ) ;
        }
      }
    }
    Serial.println();
    Serial.println("closing connection");
    delay(2000);
  }