Add c3p0 connection pooling to RDBMS module (ConnectionManager)

qqq-backend-module-rdbms/pom.xml

@@ -50,6 +50,11 @@
          <artifactId>mysql-connector-java</artifactId>
          <version>8.0.30</version>
       </dependency>
+      <dependency>
+         <groupId>com.mchange</groupId>
+         <artifactId>c3p0</artifactId>
+         <version>0.10.0</version>
+      </dependency>
       <dependency>
          <groupId>com.h2database</groupId>
          <artifactId>h2</artifactId>