Rename from 'The Netty project' to 'Netty'

Motivation:

Sonar uses the project name in the pom.xml as the project name. (no pun
intended) 4.x and master uses 'Netty' as the project name, so we should
be consistent.

Modifications:

Rename the project from 'The Netty project' to 'Netty'

Result:

Prettier SonarQube result