Proper usage of the database abstraction layer

Problem/Motivation

The module is doing bad usage of the database abstraction layer. To make matters worse, it is using GRAVE ACCENT (AKA Backtick) that is out of the SQL Standard, completely breaking the query in database engines other than MySQL.

This is the offending code:

$host_id_results = \Drupal::database()->query('SELECT `entity_id` FROM {' . $table . '} ' . 'WHERE `' . $this->bundle() . '_value` = ' . $this->id())->fetchCol();

Proposed resolution

Build the query using Database::select instead, so that DTBNG can properly translate the query to the underlying database engine.

Remaining tasks

RTBC

User interface changes

None

API changes

None

Data model changes

None